ChatScreen.java

First, i change the name bfore i realised that all normal case naming are convention{}[Dmy fauft for this[C}, secondly adding constant to eliminate magic number, thrid found a bug.[D[D[D[D[D[D[D[D[D[D[D[D[Dird[C[C[C[C[C[C[C[C[C[C[C[C[C