[Plugin: SimpleModal Login] Using Simple Modal with custom menus

How are your menus created? You should be able to add a class, unless they are being created by another plugin (even then, it is probably possible).

If you are using the WordPress Menus (Admin > Appearance > Menus) feature, you can do the following steps to manually add the necessary CSS class to the Menu item that you want to trigger SimpleModal Login:

1. On the Menus screen, click the ‘Screen Options’ link on the top right. In the “drop down”, select ‘CSS Classes’ under ‘Show advanced menu properties’.
2. Now, for the link you want to use to trigger SimpleModal Login, enter simplemodal-login under ‘CSS Classes (optional)’.
3. That Menu item should trigger SimpleModal Login when clicked!