passing control to other window

[varun chadha]

i am trying to develop a application using Tkinter in which a new
window pops out on a particular button press.though i can pass control
automatically to that window using .force_focus() method and disabling
all my widgets in previous window but the technique is not so clean.
for eg. when u click 'save' a window pops out asking for location but
u can still close your previous window using the 'cross-mark' on top
right corner with save window still open.
can anyone help me out!