A strange problem regarding form submission

So I'm working on a form :
<FORM NAME="service" METHOD="post" ACTION="submitted.aspx" ONSUBMIT="return validate()">  
 
Part of this form is a drop down list called "AssignedTo".
At the end of the validation function I have an alert:
if(validate stuff....){ alert("bobEndValidate;"+document.getElementById("AssignedTo").value) return true; }
 
The value displayed is expected. Here's my issue, in the submitted.aspx file the code Request.Form("AssignedTo") evaluates to the empty string.
Now its my understanding that once the Onsubmit evaluates to true, the Action code is run next. ...