Tension of string between two blocks

[stosw]

Homework Statement

a 3.4 kg block A and 6.0 kg block Bvec are connected by a string of negligable mass. Force FA = (12 N) acts on block A; force FB = (24 N) acts on block B. What is the tension in the string?

http://img25.imageshack.us/img25/2610/imagepn.jpg

Homework Equations

F=ma

The Attempt at a Solution

I've tried adding the forces given because they're in the same direction. I've tried subtracting the forces, but that's obviously not how to go about doing this problem.

I've solved the acceleration for each block, but I honestly don't know what to do for this problem. Could someone give a hint or two at what to do? Thanks.

 

[kellenm]

Do your some of forces for the x and y direction for both boxes.

Force of tension=mass1*a