View Compilation Error

0_0_6234775_3201.cpp: In function `int main()':
0_0_6234775_3201.cpp:42: error: `t1' undeclared (first use this function)
0_0_6234775_3201.cpp:42: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6234775_3201.cpp:42: error: `ftime' undeclared (first use this function)