Need to sum columns x,y,z on another sheet by criteria on the original sheet.

So sum columns x,y,z from sheet Detail --- 100 rows, x1:z100 - the sum
range.

Via criteria range on sheet Detail - a1:a100

Where the Detail sheet row matches [lookup?] criteria on sheet Summary k12.

Have looked at it too long!
Any assistance will be greatly appreciated.


Thanx,
- Mike