I've just started learning Mathematica. I have entered code to solve a system of differential equations, of which I know the solution. When I evaluate the notebook, I am just given my code rewritten, with no error message. I'm not sure what is wrong with my code. Any advice would be greatly appreciated.

Dsolve[{Derivative[1][A][t] + ik A[t] - (m + 1)^(.5) B[t] == 0, 
  B'[t] + (m + 1)^(.5) A[t] + m^(.5) F[t] == 0, 
  F'[t] - ik F[t] - m^(.5) B[t] == 0, 
  A[0] == 0, B[0] == 0, F[0] == 0}, 
  {A[t], B[t], C[t]}, t]