View Compilation Error

0_0_8921507_19122.c:3: error: syntax error before "isPrime"
0_0_8921507_19122.c: In function `isPrime':
0_0_8921507_19122.c:5: error: `bool' undeclared (first use in this function)
0_0_8921507_19122.c:5: error: (Each undeclared identifier is reported only once
0_0_8921507_19122.c:5: error: for each function it appears in.)
0_0_8921507_19122.c:5: error: syntax error before "flag"
0_0_8921507_19122.c:6: error: 'for' loop initial declaration used outside C99 mode
0_0_8921507_19122.c:10: error: `flag' undeclared (first use in this function)
0_0_8921507_19122.c:10: error: `false' undeclared (first use in this function)