I treid but doesnt work for me

Sorry, but if you don't show what's wrong, we can't help. Please see How do I post a question effectively?, I know what I mean. Why don't you? and Short, Self-Contained, Correct Example.

Storing a value returned from a function in a variable and returning that value from a subroutine are fairly basic operations - I'd recommend a full read of perlintro, which will show you those basics.