How to get parameter values in query string by Javascript

Sometimes, you want to get the parameter value in query string by using Javascript. In this case, you can use this function to do that:

function GetParamValue(strParamName)
{
var strReturn = "";
var strHref = window.location.href;
if ( strHref.indexOf("?") > -1 )
{
var strQueryString = strHref.substr(strHref.indexOf("?")).toLowerCase();
var aQueryString = strQueryString.split("&");
for ( var iParam = 0; iParam <>
{
if (aQueryString[iParam].indexOf(strParamName.toLowerCase() + "=") > -1 )
{
var aParam = aQueryString[iParam].split("=");
strReturn = aParam[1];
break;
}
}
}
return unescape(strReturn);
}

For example, if your URL like that: www.example.com\ProductDetail.aspx?ProductID=3
You can call:
var strProductID = GetParamValue("ProductID");