var changecity={
         mode:"iframe",
         url:"http://www.jiangshi.org/changecity.htm",
         ot:"",
         createFrame:function()
         {
            if(this.ot=="")
            {
            document.getElementById("all_city").innerHTML='<iframe id="chf" scrolling="no" width="330" height="148" src="'+this.url+'" frameborder="0"></iframe>';
            }
            else
            {
            document.getElementById("all_city").innerHTML='<iframe id="chf" scrolling="no" width="330" height="148" src="'+this.url+"?"+this.ot+'" frameborder="0"></iframe>';
            }
         },
         changeClass:function(className)
         {
            if(className=="sc")
            {
             if(!document.getElementById("chf"))
             {
               this.url="http://www.jiangshi.org/changecity.htm";
               this.createFrame();
             }
            }
            document.getElementById('all_city').className=className;
         }
}