nested functions

I am trying to use the IF function to return a false value if the combined sum of a row is not the same as either of the 1st 2 cells. If that makes any sense!

This is the formula I would like to use
=IF(SUM(g3:g9)=g1 or g2 then y if true and x if false

I thought it would be easy but I can't figure out how to do it

Please help x
I am using excel 2000