View Compilation Error

0_0_32378492_28138.cpp: In function 'int main()':
0_0_32378492_28138.cpp:17:17: error: invalid conversion from 'char*' to 'int' [-fpermissive]
    if(!isalpha(s))
                 ^
In file included from 0_0_32378492_28138.cpp:2:0:
GCC4.9.2/x86_64-w64-mingw32/include/ctype.h:102:23: note: initializing argument 1 of 'int isalpha(int)'
   _CRTIMP int __cdecl isalpha(int _C);
                       ^