Validation issue

Hi there,

I thought i’d sorted my php validation out. however, if I enter the same name twice, i get a ‘name already taken’, which is fine. If I leave the name as-is, and correctly enter all other fields, the name is ignored, and the data inserted to the database. Meaning i now have 2 of the same name being input to the db.

Can anyone help? I have inserted my form (html and php) below.

<body>
	
	<div id="container">
		

		
		<div id="header">	</div>
		
		<div id="navigation">
			
			<ul>
				<li><a href="index.php">Home </a></li>
				<li><a href="about.php"><img src="http://www.sitepoint.com/forums/images/about.jpg"> </a></li>
				<li><a href="register.php">Register </a></li>
				<li><a href="help.php">Help </a></li>
				<li><a href="faq.php">FAQ </a></li>
				
	

			</ul>
			
			
		
		</div>

			
	
		
		<div id="left_content">
			



			
		</div>
		

		
		<div id="main_content">
			
			<h3> Hello and Welcome  </h3>
			
<?php

function account_exists($column, $value) {
	$accounts = mysql_query('SELECT * FROM businesses WHERE ' . $column . ' = "' . $value . '"');

	$return = (mysql_num_rows($accounts) > 0) ? true : false;
	
	mysql_free_result($accounts);

	return $return;
}


$spam_check = ZGF;

//	Check Email Address courtesy of Dave Child:
//	http://www.ilovejackdaniels.com/php/email-address-validation/
function check_email_address($email) {

	if (!ereg("^[^@]{1,64}@[^@]{1,255}$", $email)) return false;

	$email_array = explode("@", $email);
	$local_array = explode(".", $email_array[0]);

	for ($i = 0; $i < sizeof($local_array); $i++) {
		if (!ereg("^(([A-Za-z0-9!#$%&'*+/=?^_`{|}~-][A-Za-z0-9!#$%&'*+/=?^_`{|}~\\.-]{0,63})|(\\"[^(\\\\|\\")]{0,62}\\"))$", $local_array[$i])) return false;
	}

	if (!ereg("^\\[?[0-9\\.]+\\]?$", $email_array[1])) {

		$domain_array = explode(".", $email_array[1]);

		if (sizeof($domain_array) < 2) return false;

		for ($i = 0; $i < sizeof($domain_array); $i++) {
			if (!ereg("^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]+))$", $domain_array[$i])) return false;
		}

	}

	return true;

}


	if (isset($_POST['submit'])) {
    	$business_name = ( $_POST['business_name']);
		$category = ( $_POST['category']);
		$email = ( $_POST['email'] );
		$description = ( $_POST['description'] );
		$spam_check = $_REQUEST['spam_check'];


	if (empty($business_name)) {
	  echo "<p class='form_text'>The Business Name is empty</p>";
	}
 	else if (account_exists('business_name', $business_name)) {
		 echo "<p class='form_text'> Sorry, that Business Name is already registered";
		}
	
	
	if (empty($category)) {
	  echo "<p class='form_text'>The Category is empty</p>";
	}
	
	//	Email address checks
	if (empty($email)) {
		echo "<p class='form_text'>You must enter your email address</p>";
	} else if (!check_email_address($email)) {
		echo "<p class='form_text'>Your email address is invalid</p>";
	}
	
	if (empty($description)) {
	  echo "<p class='form_text'>The Description is empty</p>";
	}

	if ($spam_check !="ZGF") {
	  echo "<p class='form_text'>Spam Check Failed</p>";
	}	
	
			
	else {
    @mysql_query( "INSERT INTO `businesses`(business_name,category,email,description) VALUES ('$business_name','$category','$email','$description')" ) or die( mysql_error() );




	    {//send email
		$business_name=stripslashes($_REQUEST['business_name']) ;
	    $email=stripslashes($_REQUEST['email']) ;
	    $category=stripslashes($_REQUEST['category']) ;
		$description=stripslashes($_REQUEST['description']) ;

		$email_message = "Business Name: \
 {$business_name} \
 \
 Email Address: \
 {$email} \
 \
  Category: \
 {$category} \
 \
 Description: \
 {$description}";




	    	mail('testemail@test.com', 'Business Reg Submission', $email_message, 'From: '.$email."\\r\
");

	    }

	echo "<p class='form_text_success'>Thanks, you have now been added to the directory.</p>";

	echo '<META HTTP-EQUIV="Refresh" Content="5; URL=thanks.php">'; 
	
	
		 }
	}

?>


			<div id="stylized" class="myform">	
			<fieldset>
				<form  action="index.php" method="post">

				<h1>Business Registration</h1>
				<p>Please enter the form below to register your business with business-reg</p>
				
				<label>Business Name
				<span class="small">Add your business name</span>
				</label>
				<input type="text" name="business_name" id="business_name" value="<?php echo $business_name; ?>" />

				<label> Category
				<span class="small">Please add a category</span>
				</label>
				<select name="category" size="1" id="category">
				  <option value="accomodation">Accomodation</option>
				  <option value="accountancy">Accountancy</option>
				  <option value="accomodation">Accomodation</option>
				 
				</select>

				<label>Business Email
				<span class="small">Add a valid address</span>
				</label>
				<input type="text" name="email" id="email" value="<?php echo $email; ?>" />

				<label>Description
				<span class="small">Please describe your business</span>
				</label>
				<textarea cols="22" rows="10" id="description" name="description"><?php echo $description; ?></textarea>
				
				<label>Spam Checker
				<span class="small">Enter the last 3 characters</span>
				<img src="http://www.sitepoint.com/forums/images/spam.jpg">
				</label>
				<input type="text" name="spam_check" id="spam_check" />
				

				<button type="submit" name="submit" id="submit"></button>
				<div class="spacer"></div>

				</form>
		
			</fieldset>
			
			

			
			</div>
			
		</div>

	</div>
	
</body>