I presume that you've created the child non-modal.
In that case, your call to GuiGetMsg() handles the operation of both windows simultaneously. If the enduser manipulates a control in the main window, it will call the appropriate event handler(s) in the main script. If the enduser uses a control in the child window, it will call the appropriate event handler(s) in the child script.
Since it's the operation of some main window control that initiates the action, then you need some handler in the main script to catch that action. The handler should test if the child script is running. If so, it should then call some function you put in the child script. That child function will do whatever it is you need to do.
For example, maybe you have a main window button that calls WM_CLICK_Something. And you've created a child object associated with the variable MyChild.wm_click_something:
IF EXISTS("MyChild") THEN DO
ret = mychild~dosomething("Hello")
END
RETURN |