how can i make a custom validation when i use the function loadstruct?

explain please, when do you plan validate?

check if two passwords inputs are same… but using loadstruct (xml) to load the structure of the form…

yes, but you want validate after user click button “register” for example?

you can check this viewtopic.php?f=17&t=15897&start=0

in your case you need just compare two fields and return true/false.