alright. what I am doing now is I have a second no initialized variable and than I check if they are the same. That works.

I was thinking about setting the unused var to 666666 or something so I know if its that value it's still to be used. But in my program userinput is required so in case the user would input 666666 it would not work correct anymore...

and if you wanna know, what I am doing is a little task for university. I have to implement a Searchtree and have to program some functions for it.

thanks guys...