View Compilation Error

121408_0_20416.c: In function `main':
121408_0_20416.c:4: error: syntax error before '/' token
121408_0_20416.c:6: error: `n' undeclared (first use in this function)
121408_0_20416.c:6: error: (Each undeclared identifier is reported only once
121408_0_20416.c:6: error: for each function it appears in.)
121408_0_20416.c:8: error: `sum' undeclared (first use in this function)
121408_0_20416.c:9: error: `i' undeclared (first use in this function)