code: function addQueryString( url, params ) {
  		var queryString = [];
  
  		if ( !params )
  			return url;
  		else {
  			for ( var i in params )
  				queryString.push( i + "=" + encodeURIComponent( params[ i ] ) );
  		}
  
  		return url + ( ( url.indexOf( "?" ) != -1 ) ? "&" : "?" ) + queryString.join( "&" );
  	}
docs: Adds (additional) arguments to given url.  @param {String} url The url. @param {Object} params Additional parameters.