How to detect a change in a global variable ?

[jbv at souslelogo.com]

Hi list,

Let's say I have a portion of a script like this :

   global myVar
   put 0 into myVar
   -- some code
   repeat until myVar > 0
   end repeat
   -- some code

and the content of global myVar being changed
in a handler of another control :

   on mouseUp
     global myVar
     put 1 into myVar
   end mouseUp

I know this is not very elegant, but my question is :
can the change in myVar be detected in a loop like
above ?
I made some tests and it doesn't seem to work...

Thank you in advance.
jbv