Recompile HomePage.cls and open it in a Web browser. Now, if we attempt to submit the form with anything other than a pair of characters from A-Z in the State field, Zen does the following:
Prevents the form from submitting.
Highlights the State field on the form.
Displays an Alert box. As part of its message, the box displays the value of the <text> element's invalidMessage attribute.
Here is how this appears in a browser: