Question

How to change the Form Action and Form id at run time. the form tag implemented on master page. please give any solution?

Answer 1

Sounds like you need to use JavaScript. You can do it as follows:

<script>
    var myForm = document.getElementById("oldFormId");
    myForm.action = "newAction";        
    myForm.id = "newFormId"​​;
<script>

Note that this will only change the id and action of the form on the given page and will not affect your actual code (because it is a client-side change). If you wanted, you could encapsulate this logic in a function which is included in your master page itself, which would make it accessible from anywhere on the site.