function zzOnFieldFocus ( field, className ) {
    if ( field.value == field.defaultValue ) {
        field.value = '';
        zzElement.removeClassName ( field, className );
    } 
}

function zzOnFieldBlur ( field, className ) {
    if ( field.value == '' ) {
        field.value = field.defaultValue;
        alert(className);
        zzElement.addClassName ( field, className );
    }
}