Comment on 'quantum dialogue'
  In this comment, we want to emphasize that when the state of the two qubit is $|0>_{B}|1>_{A}$ or $|1>_{A}|0>_{B}$, Bob's Bell basis measurement outcome can not be $|\phi ^{\pm}>$. Also, when the product state is $|0> |0>$ or $|1> |1>$, Bob's measurement outcome can not be $|\psi ^{\pm}>$. 
Qing-yu Cai