Yes this is possible: to make a contact link in the menu that points to the form lightbox you do the following:
Step 1. head over to Appearance >> Menus and create a menu item with a custom link.
To create a menu item with custom link expand ther “links” box on teh right hand side (open it) you see a box where you can create a Cusutom url and link text.
In the link box you tick a # and in the link text you type in for example “Contact”
You have now made a custom link with # as url, and now you can add the link to the menu.
Step 2. Above you open the screen and you see various options. Tick the option Link relation (XFN) and the option CSS classes. now in the menu head over to the newly created item (Contact) and add nofollow to the link relation. To the Css class of the menu item you add a class with a number for example “fl_box-13”
Step 3. Add the shortcode to the footer. Now you must go to your footer template and add the shortcode for the lighbox with your form. Presuming you already made a form in gravity with number 3 the shortcode in the footer will be:
′ <?php echo do_shortcode( ‘[formlightbox_call title=”Neem contact op” class=”13″][/formlightbox_call] [formlightbox_obj id=”13″ style=”” onload=”false”][gravityform id=”3″ name=”snel contact” title=”false” description=”false”][/formlightbox_obj]’ ) ?> ′
The object id must be 13, because it must be the same as the number in the css class.
Step 4. hide the form in the footer.
Now you don’t want the form to be visible in the footer, that would not be good so you must hide it.
For this you just put the shorcode in a div with style=”visibility-hidden”