Well, not sure why you would want to do this, but there are two alternatives.
1) Have different forms for both buttons. This would probably require using Javascript to populate a hidden field or something since the id for the record to delete or update comes from the same select.
2) Make the update & delete buttons buttons only.
<input type="button" name="frmUpdate" value="update" onclick="somefunction('update','http://...')">
<input type="button" name="frmDelete" value="delete" onclick="somefunction('delete','http://...')">
function somefunction(m,sURL)
{
switch(m)
{
case 'update':
document.formname.action=sURL;
document.formname.submit();
break;
case 'delete':
document.formname.action=sURL;
document.formname.submit();
break;
}
}
example untested.