Help! Urgent! is not the way to get an answer to your problem.
Give your post a meaningful title - to give people some idea of what the post is about.
Tell us the layout of your tables.
Working on a project today that is due tomorrow doesn't give us any idea of what you have tried; what errors you have encountered etc.
What is causing the urgency?
I have never heard of
relationship function - could you please tell us what you found?
You might try google Adding a field to an MS Access table
http://bit.ly/Pnf8jG