function GetQueryVariable(strVariableName) 
{
    var strQuery = window.location.search.substring(1);
    var astrVars = strQuery.split("&");
    
    for ( var nIdx=0; nIdx<astrVars.length; nIdx++ ) 
    {
        var pair = astrVars[nIdx].split("=");
        if ( pair[0] == strVariableName )
        {
            return pair[1];
        }
    }
    
    return null;
}