Thanks for your answer, but that's not exactly what I wanted to do. In your scenario I first check if the image is visible and then compare the image to another. But what I wanted was, first compare the image to another and then depending on whether the image is the same or not do something.
I solved it now as follows:
1. ComparePictures
I stored one picture in regions and compared it to an onscreen object
2. If...then
LastResult equals true
Now if the images are the same the "then" condition will be executed otherwise the "else" condition.
