PHP & HTML "Creating a Form" (Function within an action) Help

My issue is when i submit my form my outcome is unsucessfull.

<?php

class model {

	function __construct($url, $root, $common_model, $common_view, $alt_root) {

		$this->url = $url;
		$this->root = $root;
		$this->common_model = $common_model;
		$this->common_view = $common_view;
		$this->alt_root = $alt_root;

		$this->loader();

	}


	function loader() {

		if ($this->common_model->search_get($this->url,'Log_An_Invoice')=='View_An_Invoice') {

			$this->View_An_Invoice();
			
		} elseif ($this->common_model->search_get($this->url,'Log_An_Invoice')=='Invoice_Logged') {

			$this->Invoice_Logged();

		} else {
		
			$this->Log_An_Invoice();
			
		}

	}


	function Log_An_Invoice() {

	$this->common_view->template_header();
		
		$this->common_view->cams_style();

		$this->common_view->template_body();
		
		$this->common_view->page_title('Log An Invoice', 'Log_An_Invoice');
		
		echo '<div class="tabPane">';

                echo '<div class="tabActive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice\\';"><span><b>Log An Invoice</b></span><img src="'.$this->root.'images/gui/tab_right_active.gif" /></div>';
		
		if (($_COOKIE['talent_user_email_address'] == "paul.jackson@talent.co.uk")){	
			echo '<div id="left_actions" class="tabInactive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice/View_An_Invoice\\';" onmouseover="document.getElementById(\\'left_actions\\').className=\\'inactiveTabOver\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_over.gif\\';" onmouseout="document.getElementById(\\'left_actions\\').className=\\'tabInactive\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_inactive.gif\\';"><span><b>View An Invoice</b></span><img id="right_actions" src="'.$this->root.'images/gui/tab_right_inactive.gif" /></div>';	
		} else {}
  		
		echo '</div>';
		
		echo '
      <form class="form-signin" role="form" action="window.location.href=\\''.$this->root.'Log_An_Invoice/Invoice_Logged\\';"method="POST">
        <h2 class="form-signin-heading" style="text-align: center;">Invoice Form</h2>
        <select name="InvoiceFrom" id="InvoiceFrom" type="Text" class="form-control" required autofocus>
            <option value="" selected>Please Select One...</option>
            <option value="Talent">Talent</option>
            <option value="Redwood">Redwood</option>
            <option value="Hillingdon">Hillingdon</option>
        </select>
        <input name="InvoiceTo" type="text" class="form-control" placeholder="Invoice To" required>
        <input name="ContactName" type="text" class="form-control" placeholder="Contact Name" required>
        <input name="ContactNumber" type="text" class="form-control" placeholder="Contact Number" required>
        <input name="Email" type="email" class="form-control" placeholder="Contact Email" required>
        <textarea name="InvoiceAddress" type="text" class="form-control" placeholder="Contact Address" rows="5" required></textarea>
        <input name="PoNo" type="text" class="form-control"  placeholder="PO No" required>
        <textarea name="Details" type="text" class="form-control" placeholder="Invoice Details (Description)" rows="5" required></textarea>

        <div class="input-group">
        <span class="input-group-addon">&pound;</span>
        <input name="InvoiceAmount" class="form-control" placeholder="Total Amount" type="number" required>
        </div>

        <label class="checkbox" >
          <input type="checkbox" value="0" style="text-align: center;" required> I accept that the following information is correct.
        </label>
        <button type="button" type="submit" >Log Invoice</button>
      </form>';

	$this->common_view->template_footer();
	
	}


	function View_An_Invoice() {
		
		
	$this->common_view->template_header();
		
		$this->common_view->cams_style();

		$this->common_view->template_body();
		
		$this->common_view->page_title('View An Invoice', 'View_An_Invoice');
		
		echo '<div class="tabPane">';
		
		echo '<div id="left_actions" class="tabInactive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice\\';" onmouseover="document.getElementById(\\'left_actions\\').className=\\'inactiveTabOver\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_over.gif\\';" onmouseout="document.getElementById(\\'left_actions\\').className=\\'tabInactive\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_inactive.gif\\';"><span><b>Log An Invoice</b></span><img id="right_actions" src="'.$this->root.'images/gui/tab_right_inactive.gif" /></div>';	
	
		
		echo '<div class="tabActive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice/View_An_Invoice\\';"><span><b>View An Invoice</b></span><img src="'.$this->root.'images/gui/tab_right_active.gif" /></div>';
		
		echo '</div>';
	
		// Make a MySQL Connection
		mysql_connect("localhost", "Form", "") or die(mysql_error());
		mysql_select_db("talent_intranet") or die(mysql_error());
	
		// Get all the data from the "example" table
		$result = mysql_query("SELECT * FROM Form")
		or die(mysql_error());
	
		echo '<div style="margin-left:5px;margin-right:5px;" class="search_results_header" align="left">
			  <table style="border-collapse:collapse;" cellpadding="2" cellspacing="0" border="0" width="100%">
			    <tbody><tr>
				  <td colspan="7" class="td_header" height="30" width="100%"><b>Approvals</b><div style="float:right;">
					<button type="button" href="www.talnet.co.uk/intranet/Log_An_Invoice">Log An Invoice</button><button type="button" href="www.talnet.co.uk/intranet/">Home</button>
					</div></td>
				</tr>
				<tr>
				  <td class="td_header" height="30" width="4%">ID</td>
				  <td class="td_header" height="30" width="6%">Invoice From</td>
				  <td class="td_header" height="30" width="15%">Invoice To</td>
				  <td class="td_header" height="30" width="7%">Invoice Address</td>
				  <td class="td_header" height="30" width="6%">Contact Name</td>
				  <td class="td_header" height="30" width="7%">Contact Number</td>	
				  <td class="td_header" height="30" width="22%">Email</td>
				  <td class="td_header" height="30" width="12%">Po No</td>
				  <td class="td_header" height="30" width="10%">Details</td>
				  <td class="td_header" height="30" width="10%">Invoice Amount</td>
				  <td class="td_header" height="30" width="10%">Date Submitted</td>
				  <td class="td_header" height="30" width="10%">Submitted By</td>
				</tr>
			  </tbody></table>
			  </div>
			  <div style="padding-left:5px;padding-right:5px;padding-bottom:5px;" align="left">
			  <div class="search_results" style="height:175px;overflow-y:auto;overflow-x:auto;" align="left">
			  <table style="border-collapse:collapse;" cellpadding="2" cellspacing="0" width="100%">
				<tbody>';
		// keeps getting the next row until there are no more to get
		while($row = mysql_fetch_array( $result )) {
		// Print out the contents of each row into a table
		echo '<tr><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['id'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['InvoiceFrom'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['InvoiceTo'];
		echo '</font></td><td class="td_header" height="30" width="25%"><font size="1">';
		echo $row['InvoiceAddress'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['ContactName'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['ContactNumber'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['Email'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['PoNo'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['Details'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">&pound;';
		echo $row['InvoiceAmount'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['Submitted'];
		echo '</font></td><td class="td_header" height="30" width="15%"><font size="1">';
		echo $row['SubmittedBy'];
		echo "</font></td></tr>";
		}
	
		echo "</tbody></table></div></div>";
		
		mysql_close();
		
		$this->common_view->template_footer();
		}
		
	function Invoice_Logged() {

		$this->common_view->template_header();
		
		$this->common_view->cams_style();

		$this->common_view->template_body();
		
		$this->common_view->page_title('Invoice Logged', 'Invoice_Logged');
		
		echo '<div class="tabPane">';
		
		echo '<div id="left_actions" class="tabInactive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice\\';" onmouseover="document.getElementById(\\'left_actions\\').className=\\'inactiveTabOver\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_over.gif\\';" onmouseout="document.getElementById(\\'left_actions\\').className=\\'tabInactive\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_inactive.gif\\';"><span><b>Log An Invoice</b></span><img id="right_actions" src="'.$this->root.'images/gui/tab_right_inactive.gif" /></div>';
		
		if (($_COOKIE['talent_user_email_address'] == "paul.jackson@talent.co.uk")){	
			echo '<div id="left_actions" class="tabInactive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice/View_An_Invoice\\';" onmouseover="document.getElementById(\\'left_actions\\').className=\\'inactiveTabOver\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_over.gif\\';" onmouseout="document.getElementById(\\'left_actions\\').className=\\'tabInactive\\';document.getElementById(\\'right_actions\\').src=\\''.$this->root.'images/gui/tab_right_inactive.gif\\';"><span><b>View An Invoice</b></span><img id="right_actions" src="'.$this->root.'images/gui/tab_right_inactive.gif" /></div>';	
		} else {}
		
		echo '<div class="tabActive" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice/Invoice_Logged\\';"><span><b>Invoice Logged</b></span><img src="'.$this->root.'images/gui/tab_right_active.gif" /></div>';
  		
		echo '</div>';
		
		$Submitted = date("d-m-Y");

		$SubmittedBy = $_COOKIE['talent_user_email_address'];

		$errors = array();

		$required = array(
		    'InvoiceFrom'   =>'This is required',
		    'InvoiceTo'     =>'This is required',
		    'InvoiceAddress'=>'This is required',
		    'ContactName'   =>'This is required',
		    'ContactNumber' =>'This is required',
		    'Email'         =>'This is required',
		    'PoNo'          =>'This is required',
		    'Details'       =>'This is required',
		    'InvoiceAmount' =>'This is required'
		);
		
		if ('POST' === $_SERVER['REQUEST_METHOD'])
		{
		    foreach ($required as $field => $error)
		    {
		        $isEmpty = 0 == strlen(trim($_POST[$field]));
		
		        if ($isEmpty) {
		            $errors[] = $error;
		        }
		    }

		    if ( ! filter_var($_POST['Email'], FILTER_VALIDATE_EMAIL)) {
		        $errors[] = 'Email must be a valid email address';
		    }
		
		    if ( ! preg_match('~^[0-9.]+$~i', $_POST['InvoiceAmount'])) {
		        $errors[] = 'Invoice amount value is invalid';
		    }
		
		
		    if(!isset($_POST['InvoiceFrom'])){
		          $errors[] = '<li>You forgot to select the company!</li>';
		    }
		
		
		    if (empty($errors))
		    {
		       $con = mysql_connect("localhost","Form","","talent_intranet");
		       if(!$con){
		        die('Could not connect: ' .mysql_error());
		       }
		        $db_selected = mysql_select_db("talent_intranet", $con);

		        if (!$db_selected){
		            die ("Can\\'t select db : " . mysql_error());
		            }
		
		
		        $sql = sprintf(
		            "INSERT INTO
		                Form
		            (InvoiceFrom, InvoiceTo, InvoiceAddress, ContactName, ContactNumber, Email, PoNo, Details, InvoiceAmount, Submitted, SubmittedBy )
		                VALUES
		            ('%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s','$Submitted','$SubmittedBy');",
		            mysql_real_escape_string($_POST['InvoiceFrom']),
		            mysql_real_escape_string($_POST['InvoiceTo']),
		            mysql_real_escape_string($_POST['InvoiceAddress']),
		            mysql_real_escape_string($_POST['ContactName']),
		            mysql_real_escape_string($_POST['ContactNumber']),
		            mysql_real_escape_string($_POST['Email']),
		            mysql_real_escape_string($_POST['PoNo']),
		            mysql_real_escape_string($_POST['Details']),
		            mysql_real_escape_string($_POST['InvoiceAmount'])
		        );
		        $res = mysql_query($sql, $con);
		
		        }
		
		        if(!$res){
		          die ("Can\\'t run query : " . mysql_error());
		        }

		        $errors[] = mysql_error($con);

		        mysql_close($con);
			echo'<h1>Your Invoice Was Logged Successfully!</h1>';
		
			echo'<button type="button" href="www.talnet.co.uk/intranet/Log_An_Invoice">Log An Invoice</button> <br> <button type="button" href="www.talnet.co.uk/intranet/">Home</button> ';

			} else {
		
			echo'<h1>Your Invoice Was Not Successful!</h1>';
			
			echo'<button type="button" onclick="window.location.href=\\''.$this->root.'Log_An_Invoice\\';">Retry</button> <br> <button type="button" onclick="window.location.href=\\''.$this->root.'\\';">Home</button> ';
		
			echo'<h2>Please contact your system administrator. Inform of the following message.</h2>';
			
			if (count($errors)){
				foreach ($errors as $error){
					echo $errors;
				}
			}
			
			error_reporting(E_ALL);
			
			}
		
			$this->common_view->template_footer();
		    		
		}
	}


?>

None of Invoice_Logged funtion is wrong. i dont understand how make a form post to a function that injects.

Help please.

Thanks
-Jamie