Firstly, think of how you would want to do it, write it down.
Work out some code that looks like it should do what you wanted.
try it, what does it do?
if it doesnt work, post it, explain what you're getting you didnt expect, and ask for assistance.
Dont post just asking for us to do it for you
Did I just hear "You gotta help us, Doc. We've tried nothin' and we're all out of ideas" ? Is this you? Dont let this be you! I will put in as much effort as you seem to.