How do I do post form submission processing?

Hello,
Just as I have an OnSubmit intrinsic event do I have something like an
OnAfterSubmit event?
If I don't then what do I do if I need to do processing immediately after
form submission on the HTML page which contains the form?

Code Sample :-
.
.
.
<FORM name="ProductForm" action="c.asp" method="post">
         <INPUT TYPE="text" NAME="FIELD1" VALUE="VAL1" SIZE="5"/>
         <INPUT type="submit" value="SUBMIT FORM"/>
</FORM>
.
.
.
After form submission, I need to change the action attribiute to some
other asp file eg.

<FORM name="ProductForm" action="d.asp" method="post">

  through DHTML after form submission.How do I do it?


Regards,

AMIT