Question

When a user makes a change to the input field “vmake” i want a hidden input called “carsearch” to change its value from False to True. The default value of the hidden input is False. Here is my script:

$(function(){
    $("#vmake").change(function(){
       $("#carsearch").val('True');
    });
});

If its helful the HTML for the hidden input is:

<input id="carsearch" type="hidden" name="carsearch" value="False" />

Answer 1

You set val as an attribute to your input element. It should be value.

Sample

<input id="carsearch" type="hidden" name="carsearch" value="False" />
<select id="vmake">
    <option>1</option>    
    <option>2</option>
</select>


$(function(){
    $("#vmake").change(function(){
        alert("Before = " +  $("#carsearch").val());
        $("#carsearch").val('True');
        alert("After = " + $("#carsearch").val());        
    });
});

Check out this jsFiddle Demonstration