Pb by using setItemText

Dear all,
I want to update the item text when the user execute a doubleclick. to do that i created this code :
unction F_RenameNodeTree ( id) {
var NewLabel = prompt(‘Enter new text’,ListOfPhaseTree.getItemText(id));
if ( NewLabel )
this function is called on event ListOfPhaseTree.setOnDblClickHandler(F_RenameNodeTree);

I can renamed a node but the renaming isn’t saved ???
for your information the tree uses a dataprocessor in php and i use the standard library then the function Updateitem isn’t available.

Dear all,
I’m sorry i found my answer in the dthmlx documentation