View Compilation Error

147257_0_770.c: In function `main':
147257_0_770.c:8: error: `bool' undeclared (first use in this function)
147257_0_770.c:8: error: (Each undeclared identifier is reported only once
147257_0_770.c:8: error: for each function it appears in.)
147257_0_770.c:8: error: syntax error before "flag"
147257_0_770.c:35: error: `flag' undeclared (first use in this function)
147257_0_770.c:35: error: `true' undeclared (first use in this function)
147257_0_770.c:39: error: `false' undeclared (first use in this function)