Click item on tree,the userdata is "undefined"

when I used follow code to click item on tree,the userdata’s value is “undefined”:


    var url = tree.getUserData(id,“url”);


return true;


and the XML like this:


I saw almost about this problem in the kb, but I still can’t solve the problem,please help,thanks!

The same code works correctly locally.
Be sure that old xml, without userdata, is not cached