Thanks for the reactions,
Unfortunally i can't seem to get your script to work C.pfaffenbichler.
And the collage tool you give JJMack doesn't let me use a fixed width for the template and a reletive width for the smartobjects. as the combined with of the smart objects should not exceed the template with but should be equal (or less if the height exeeds the template height)
I'm not that great of a javascripter so i don't know how to alter it.