I wonder if this is a PHP issue, as it looks like a form that is processed by PHP (but I'm only guessing here). There is JS involved, but is that for submitting the form or just checking the input before sending? Do you have a PHP script for processing this form? Normally there will be a link to it inside the action quotes here:
<form name="form1" id="frmindex" method="post" action="" >
So in your code file, what is between those quotes, if anything?