Update README.md

README.md

@@ -226,7 +226,7 @@ $('#test').inputmask('999[-AAA]');
 ```
 While the field has focus and is blank, users will see the full mask `___-___`.
 When the required part of the mask is filled and the field loses focus, the user will see `123`.
-When both the required and optional parts of the mask are filled out and the field loses focus, the user will see `123-abc`.
+When both the required and optional parts of the mask are filled out and the field loses focus, the user will see `123-ABC`.
 
 ### aliases option