// Requires prototype.js

function validateEmail(field, regexp) {
    var result = regexp.test($F(field));
    
    if (result == false) {
        Element.hide('emailRequired');
        Element.hide('emailValidator');
    
        if ($F(field).length == 0) {
            Element.show('emailRequired');
        } else {
            Element.show('emailValidator');
        }
        Field.focus(field);
    }
    return result;
}