[jquery] JavaScript: how to change form action attribute value based on selection?

I'm trying to change the form action based on the selected value from a dropdown menu.

Basically, the HTML looks like this:

<form class="search-form" id="search-form" method="post" accept-charset="UTF-8" action="/search/user">
<select id="selectsearch" class="form-select" name="selectsearch">
<option value="people">Search people</option>
<option value="node">Search content</option>
</select>

<label>Enter your keywords: </label>
 <input type="text" class="form-text" value="" size="40" id="edit-keys" name="keys" maxlength="255" />

<input type="submit" class="form-submit" value="Search" id="edit-submit" name="search"/>
</form>

If "people" is selected, (which it is by default), the action should be "/search/user", and if content is selected, the action should be "/search/content"

I'm still searching around, but haven't been able to find out how to do this.

Is required that you have a form?
If not, then you could use this:

<div>
    <input type="hidden" value="ServletParameter" />
    <input type="button" id="callJavaScriptServlet" onclick="callJavaScriptServlet()" />
</div>

with the following JavaScript:

function callJavaScriptServlet() {
    this.form.action = "MyServlet";
    this.form.submit();
}

Simple and easy in javascipt

<script>

  document.getElementById("selectsearch").addEventListener("change", function(){

  var get_form =   document.getElementById("search-form") // get form 
  get_form.action =  '/search/' +  this.value; // assign value 

});

</script>

It's better to use

$('#search-form').setAttribute('action', '/controllerName/actionName');

rather than

$('#search-form').attr('action', '/controllerName/actionName');

So, based on trante's answer we have:

$('#search-form').submit(function() {
    var formAction = $("#selectsearch").val() == "people" ? "user" : "content";
    $("#search-form").setAttribute("action", "/search/" + formAction);
}); 

Using setAttribute can save you a lot of time potentially.

If you only want to change form's action, I prefer changing action on-form-submit, rather than on-input-change. It fires only once.

$('#search-form').submit(function(){
  var formAction = $("#selectsearch").val() == "people" ? "user" : "content";
  $("#search-form").attr("action", "/search/" + formAction);
});