var common = {

          getQueryString : function(name){

            var reg = new RegExp('(^|&)' + name + '=([^&]*)(&|$)', 'i');

            var r = '';

            try{

                r = location.href.split('?')[1].match(reg);

            }catch(err){}

            if (r != null && r != 'undefined') {

                return unescape(r[2]);

            }

            return null;

          }

      }