JavaScript How To Get QueryString

Below is written by my EE friend, ryancys. Happen to see this piece of code (posted in Experts-Exchange) and so might as well post it here. Below JavaScript function will return the value part of a querystring given the named value.

function querystring(name) // returns a named value from the querystring yourpage.html?xyz=123
{
    var tmp = location.search.substring(1);
    var i = tmp.toUpperCase().indexOf(name.toUpperCase()+"=");

    if (i>= 0)
    {
        tmp = tmp.substring(name.length+i+1);
        i = tmp.indexOf("&");
        return unescape(tmp = tmp.substring(0,(i>=0) ? i : tmp.length));
    }

    return("");
}

Edited on 10 Nov 2007: The post was made by respected expert ryancys but original author is someone else.