View Compilation Error

0_0_4672036_3867.c: In function `main':
0_0_4672036_3867.c:12: error: `m1' undeclared (first use in this function)
0_0_4672036_3867.c:12: error: (Each undeclared identifier is reported only once
0_0_4672036_3867.c:12: error: for each function it appears in.)
0_0_4672036_3867.c:16: error: `m2' undeclared (first use in this function)