Call All The Validation Functions From A File Call Functions.js?

I have several form in my site, that validate on onsubmit.I call all the validation functions from a file call functions.js.Here is a sample of the code that is working:

<form name="contact" action="contact-insert.php method="post" onSubmit="return checkform()">
<label class='SubHeadlbl' for='TextField1'><?php echo IDS_EFORMNAME?><br></label>
<input type='text' name='dfname' class='text_field' id='dfname1' size='70' maxlength='40'/>
</form>

all the other forms are not working. all have the same structure:

<form name="frm1000" action="frm1000-insert.php method="post" onSubmit="return checkform1000()">
<label class='SubHeadlbl' for='TextField1'><?php echo IDS_EFORMNAME?><br></label>
<input type='text' name='dfname' class='text_field' id='dfname1000' size='46' maxlength='40'/>
</form>

I don't know what is happening only one for work all the others don't.