Hello List, I've a problem with dtml-tree. When I click on the first "plus sign" the branches may be expanded, or nothing may be happen or one of the other branches may be expanded. The same behaviour occurs with the attempt to collapse or expand the other branches. Dtml-code: <dtml-tree branches="getBranches"> branch: <dtml-var expr="__str__"> Product-code: class TestBranch: def __init__(self, str= "a"): self.str = str def getBranches(self): if not "x" in self.str: return [TestBranch(self.str + "x")] else: return None def __str__(self): return self.str def getBranches(self): return [TestBranch("a"), TestBranch("b"), TestBranch("c")] Do you have an idea, what I make wrong? Many thanks in advance, Ulla.