I hope anyone can help me. My problem is that i have a struts/ajax webapp and in one form, need to show a checkbox tree. It seems easy, and with the checktree.js itīs too easy. The real problem appears when I need to use, in the same form page, the prototype library to make things like autocomplete some fields on the form by using Ajax. In Firefox it works, but in IE shows the next javascript error: "the object donīt admit the property or method xxxxxxxxx" where xxxxxxxx represents the method for initializing the checktree. And the checktree is no longer a real checktree, become a kind of tree without checkboxes. If I forgot the autocomplete function, i.e., donīt use the prototype library, the checktree work corrently.