[javascript] How to use JavaScript to change the form action

My current code is as follows:

<div class="fr_search">   
  <form action="/"  accept-charset="UTF-8" method="post" id="search-theme-form">
  .......
  </form>
</div>

Now I want to write a function to change the form action and method, when a condition is met. How do I write this code?

For example,

function test() {
   if (selectedIndex === 1)....
} // How do I write this code?

Try this:

var frm = document.getElementById('search-theme-form') || null;
if(frm) {
   frm.action = 'whatever_you_need.ext' 
}

I wanted to use JavaScript to change a form's action, so I could have different submit inputs within the same form linking to different pages.

I also had the added complication of using Apache rewrite to change example.com/page-name into example.com/index.pl?page=page-name. I found that changing the form's action caused example.com/index.pl (with no page parameter) to be rendered, even though the expected URL (example.com/page-name) was displayed in the address bar.

To get around this, I used JavaScript to insert a hidden field to set the page parameter. I still changed the form's action, just so the address bar displayed the correct URL.

function setAction (element, page)
{
  if(checkCondition(page))
  {
    /* Insert a hidden input into the form to set the page as a parameter.
     */
    var input = document.createElement("input");
    input.setAttribute("type","hidden");
    input.setAttribute("name","page");
    input.setAttribute("value",page);
    element.form.appendChild(input);

    /* Change the form's action. This doesn't chage which page is displayed,
     * it just make the URL look right.
     */
    element.form.action = '/' + page;
    element.form.submit();
  }
}

In the form:

<input type="submit" onclick='setAction(this,"my-page")' value="Click Me!" />

Here are my Apache rewrite rules:

RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} !-f
RewriteRule ^/(.*)$ %{DOCUMENT_ROOT}/index.pl?page=$1&%{QUERY_STRING}

I'd be interested in any explanation as to why just setting the action didn't work.

If you're using jQuery, it's as simple as this:

$('form').attr('action', 'myNewActionTarget.html');