Code
            $.ajax({
               type: "POST",
               url: "Povince_Server.aspx",
               data: "dm="+id,
               success: function(msg){
               area.length=0;
               area.options.add(new Option("请选择",0));
               if(msg!="")
               {
                   var str= new Array(); 
                       str=msg.split("/");
                       for (i=0;i<str.length ;i++ )    
                       {    
                           if(str[i].toString()!="")
                           {
                               var small = new Array();
                                   small = str[i].toString().split(",");
                                   area.options.add(new Option(small[1].toString(),small[0].toString()));
                           }
                       }
                   }
               }
            });