How to pass user name

From the below I have a form where the user inputs their username and password…

the pages is at www.meadowlarkco.com/indexnewsite_test7.htm

and I want to pass just the username to the form:

<script type=“text/javascript”>

function OnSubmitForm()

{

if(document.myform.operation[0].checked == true)

{

document.myform.action ="https://webtrace.etdatacenter.com/webtrace.aspx?accesstype=autologin&cust=id_015&user=ALLHAIL";  

}

else

if(document.myform.operation[1].checked == true)

{

document.myform.action ="https://carrierconnect.etdatacenter.com/Default.aspx?accesstype=autologin&cust=id_015&user=templateuser";  

}

return true;

}

</script>

<form name=“myform” target=“_blank” method=“post” action=“” onsubmit=“return OnSubmitForm();”>
<fieldset>
<legend><font color=“#FFFFFF”>LOGIN</font></legend>
username: <input type=“text” name=“username”/><br /><br />
password: <input type=“password” name=“password”/><br />
<input type=“radio” name=“operation” value=“1” checked=“checked”/><font size=“-1”>Customer Tracking</font>
<input type=“radio” name=“operation” value=“2” /><font size=“-1”>Web Booking </font>
<input type=“submit” name=“submit” value=“submit” />
</fieldset>

</form>

So if the user chooses the second option for carrier connect and I want to pass the user name filled in would I change templateuser from the url to username from my form?

thanks

https://carrierconnect.etdatacenter.com/Default.aspx?accesstype=autologin&cust=id_015&user=templateuser