View Compilation Error

0_0_8501322_24326.cpp: In function `void pre()':
0_0_8501322_24326.cpp:38: error: `tm' undeclared (first use this function)
0_0_8501322_24326.cpp:38: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8501322_24326.cpp: In function `void after()':
0_0_8501322_24326.cpp:52: error: `tm' undeclared (first use this function)