How to do if greater than or equal to

I have two numbers. I wish to produce a value in a cell that can only be equal to the sum of two cells A,B if it does not exceed the value in another cell Y, otherwise it can be A,B< or = Y.

I have =IF(S42< C43, S42, C43) but your way shows me that the cell will deliver either the minimum of a+b or y hmm pretty not bad ...

I also need it to display a+b or y but right now it's just stating TRUE

Make that, nevermind ... 15 hours of excel in a row makes for a weary daddy. Excel retained my last function in the cell but didn't display it in the ribbon. May be time for a reboot.

Cheers,