Low Fat Strawberry Poke Cake

1 box white cake mix
1 can diet 7-up soda, sierra mist (or whatever you have available)
1 box Strawberry Jello
Cool Whip

Mix cake mix with one can of diet soda and bake as directed on the box. After cake has cooled, use a fork and poke holes all over the top of the cake. Mix one box of strawberry jello with one cup of cold water until mixture has dissolved. Pour Jello over the top of the cake. Top with Cool Whip (i used Sugar-free). Enjoy!!