View Compilation Error

0_0_36706794_29023.cpp: In function 'int main()':
0_0_36706794_29023.cpp:18:12: error: 'i' was not declared in this scope
       if(t[i] == 'a' || t[i] == 'e' || t[i] == 'i' || t[i] == 'o' || t[i] == 'u')
            ^
0_0_36706794_29023.cpp:22:17: error: 'i' was not declared in this scope
       cout << t[i];
                 ^