how to get query sring value in javascript

we use the following code snippet to get query string value in java script

function one()
{
var quer_val=getParameterByName("query_name ");
}

function getParameterByName(name) {
name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
var regexS = "[\\?&]" + name + "=([^&#]*)";
var regex = new RegExp(regexS);
var results = regex.exec(window.location.search);
if (results == null)
return "";
else
return decodeURIComponent(results[1].replace(/\+/g, " "));
}