Complied code not working

I have a matlab function that works fine inside the matlab environment, but gives an error message when run as a compiled program. Below is a code snippit about the location of the error message;

City = 'A';
while (City ~= 'W') && (City ~= 'L')
    City = input('Enter ''W'' for Wellington, ''L'' for Lower Hutt > ', 's');
    City = upper(City);
end; % while

The following is the error message when run in a Windows (Win 7 64 bit) shell;

Enter 'W' for Wellington, 'L' for Lower Hutt > W
Operands to the || and && operators must be convertible to logical scalar values
.

Error in erosionimages (line 91)

MATLAB:nonLogicalConditional

Clearly the boolean condition is okay when first entering the while loop (otherwise I'd never get to the input line). I get the same result if I enter 'w', 'W', or 'x'. Line 91 is the end statement.

Answer 1

[Image Analyst]

They're probably entering more than one character. Try this:

City = upper(City(1));