Wait for pop up window

[gifog]

Hi. Searched everywhere, but did not find what I am looking for. Am newbie.

I want the script to wait for a certain window to pop, then proceed. Of course without it consuming all the CPU. Have tried WinWaitActive, but this only works if the pop up window also becomes active. The program that brings up the pop up window is just one of a few running on the laptop, which means the pop up does not always become active (depending on what else is happening).

[johnmcloud]

WinWait