View Compilation Error

0_0_9767811_23110.c: In function `insort':
0_0_9767811_23110.c:9: error: `a' undeclared (first use in this function)
0_0_9767811_23110.c:9: error: (Each undeclared identifier is reported only once
0_0_9767811_23110.c:9: error: for each function it appears in.)