Multiple functions within one cell not sure "if" will work

[Triscia]

I have a spreadsheet and in j15 I want it to show 0 if cell I15 is blank and if it is not. I want it to add cells c15:e15 and subtract cell I15. I can't seem to figure out how to perform this little formula. TIA!
Trish

[Ron Coderre]

Try this:
=IF(I15<>"",SUM(C15:E15)-I15,0)

Does that help?

[Triscia]

No, it didn't return anything if I input an amount in I15.

This is what I would really like to happen. Cell J15 would be empty. When I enter anything into cells c15 through e15 it would remain empty until something is entered into I15. When something is entered into I15 the formula would kick in C15:e15 - I15 and the sum would show in J15. I hope this isn't too confusing. TIA!
Trish

[Triscia]

I think it might have worked. I actually had a conditional formatting and I think that was making it read funny or not at all. Thanks!!!!