check URL parameter with Jquery

Hi,

I need to be able to check the URL parameter for "subjectId" and if it is a certain value (say like 6) then show a form.
Here is what I have so far but it doesnt work.

	<script>
function GetURLParameter(sParam)
{
    var sPageURL = window.location.search.substring(1);
    var sURLVariables = sPageURL.split('&');
    for (var i = 0; i < sURLVariables.length; i++) 
    {
        var sParameterName = sURLVariables[i].split('=');
        if (sParameterName[0] == sParam) 
        {
            return sParameterName[1];
        }
    }
}​
</script>
<script>
var Id = GetURLParameter('subjectId');
if (Id = 6) {
	$("#contactForm").show();
			}
			else {
				$("#contactForm").hide ();
			}
</script>

Select allOpen in new window