在js 中根據 url 擷取其參數

 function Edit()
         {
          var  url  =   window.location+"" ;
       
           var id=''; 
            if (url.indexOf('&')==-1)
            {
              id=  url.substring(url.indexOf("id=")+3,url.length); 
            }
            else
            {    
            var temp=url.indexOf("&");
          
            id=url.substring(url.indexOf("id=")+3,url.indexOf("&"));
            
          
            }
            alert(id);
             
           var page=''
             
             var urlpage=url.substring(url.indexOf("page="),url.length);
             
              if (urlpage.indexOf("page=")!=-1)
              {  
              
                 if (urlpage.indexOf("&")==-1)
                 {
                  page=urlpage.substring(urlpage.indexOf("page=")+5,urlpage.length);
                 }
                 else
                 {
                   page=urlpage.substring (urlpage.indexOf("page=")+5,urlpage.indexOf("&"));
                 }
              }
             
             alert(page);
             alert(urlpage);
             
             
        var  usersn="";
        
          var urlsn=url.substring(url.indexOf("usersn="),url.length);
           if (urlsn.indexOf("usersn")!=-1)
           {
              if (urlsn.indexOf("&")==-1)
              {
                usersn=urlsn.substring(urlsn.indexOf("usersn=")+7,urlsn.length);
              }
              else
              {
                 usersn=urlsn.substring(urlsn.indexOf("usersn=")+7,urlsn.indexOf("&"));
              }
           }
           
           alert(usersn);
           
           
           
           
            var username="";
            
             var urlname=url.substring(url.indexOf("username="),url.length)
              if (urlname.indexOf("username")!=-1)
                  {
                     if(urlname.indexOf("&")==-1)
                    { 
                 
                     username=urlname.substring (urlname.indexOf("username=")+9,urlname.length);
                     
                    }
                    else 
                    {
                    username=urlname.substring(urlname.indexOf("username=")+9,urlname.indexOf("&"));
                    
                    }
                    
                  }
                  
                alert(username);
                  
                  
            
          
              
                 
   
          
        
           
          
         }