获取url参数，替换特殊字符

 function GetQueryString(name){
         var reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
         var r = window.location.search.substr(1).match(reg);
         if(r!=null){
             var b = decodeURI(r[2]).
                 replace(/\+/g," ").
                 replace(/%2B/g,"+").
                 replace(/%22/g,'"').
                 replace(/%27/g,"'").
                 replace(/%2F/g,"/").
                 replace(/%23/g,"#").
                 replace(/%3D/g,"=").
                 replace(/%26/g,"&").
                 replace(/%40/g,"@").
                 replace(/%3B/g,"；").
                 replace(/%3F/g,"?").
                 replace(/%2C/g,",").
                 replace(/%24/g,"$");
             return  b
         }
         return null;
     }