View Compilation Error

0_0_31493341_20611.cpp: In function 'int main()':
0_0_31493341_20611.cpp:22:21: error: 'a' was not declared in this scope
             else if(a[i]>='B'&&a[i]<='Z'&&a[i]!='A'&&a[i]!='E'&&a[i]!='I'&&a[i]!='O'&&a[i]!='U')
                     ^