How to make childern follow the darggable parent element?

Hi all,

I’m making a draggable annotation-ish button.When click the button, an annotation will popup.While drag the annotation button, the msg box popup and follow it’s position.All things working fine at this part but I find a problem that I can also drag the annotation popup to move the hole element’s position but not only the annotation button…could anyone give me some hints for how I can only drag the button(the parent) and affect the childeren’s position(the annotation popup),or is it possible…?