View Compilation Error

0_0_8302692_27417.cpp: In function `int main()':
0_0_8302692_27417.cpp:10: error: `revers' undeclared (first use this function)
0_0_8302692_27417.cpp:10: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8302692_27417.cpp: In function `void revers()':
0_0_8302692_27417.cpp:15: error: `void revers()' used prior to declaration