View Compilation Error

217135_0_3318.cpp: In function `int main()':
217135_0_3318.cpp:5: error: `duoble' undeclared (first use this function)
217135_0_3318.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
217135_0_3318.cpp:5: error: expected `;' before "a"
217135_0_3318.cpp:6: error: `a' undeclared (first use this function)