View Compilation Error

0_0_38147186_31354.c: In function 'main':
0_0_38147186_31354.c:17:8: error: 'xmod2' undeclared (first use in this function)
     if(xmod2)
        ^
0_0_38147186_31354.c:17:8: note: each undeclared identifier is reported only once for each function it appears in