Ok, thx. Not exactly what i was looking for, but it should do it.
One thing about the ListBox. When i multiselect some entrys, the background of the selected entrys changes to blue, color of the text changes to white, business as usual. But when i select entrys more downwards in the list, the color of the text in the selections (all of them selected so far) switches back to black, which makes it a lot more diffcult to read (black text at blue back). Is this behaviour intended? (how can i avoid it?)