View Compilation Error

0_0_38380426_20416.c: In function 'main':
0_0_38380426_20416.c:4:2: error: unknown type name 'bool'
  bool isprime(int a);
  ^
0_0_38380426_20416.c: In function 'isprime':
0_0_38380426_20416.c:20:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=2;i<a;++i)
  ^
0_0_38380426_20416.c:20:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code