function $QueryString()
{
   this.Keys = new Array();
   this.Values = new Array();

   var query = window.location.search.substring(1);
   var pairs = query.split("&");
   
   for(var i=pairs.length-1; i>=0;i--)
   {
      var pos = pairs[i].indexOf('=');
      if (pos >= 0)
      {
         var name = pairs[i].substring(0,pos);
         var value = pairs[i].substring(pos+1);
         this.Keys[this.Keys.length] = name;
         this.Values[this.Values.length] = value;      
      }
   }
}

$QueryString.prototype.Get = function(key)
{
   var value = null;
   for( var i=this.Keys.length-1; i>=0; i--)
   {
      if( this.Keys[i] == key )
      {
         value = this.Values[i];
         break;
      }
   }
   return value;
}

var QueryString = new $QueryString();