This suggestion might work for you...
Rather than linking to the form itself, you could add the form as an article to your site (which would maintain your header, etc.) rather than trying to link directly to the form. To do that, you would create an article and then enter the following code as the page content:
(obviously replacing 'formname' with your actual form name, taken from the 'Name' field - not the Title - of your form.) Then, publish the article.
Now, if you have a Hidden menu, you can add the article to it. If you DON'T have a hidden menu, you can create it as follows:
- Go to Administration > Menus > Menu Manager
- Click the 'New' icon on the upper right-hand side.
- Fill in the fields - you could use something like this:
- Unique Name: hidden
- Title: Hidden Menu
- Description: Hidden Menu
- Module Title: hiddenmenu
- Now go to Menus > Hidden Menu
- Click on the 'New' icon on the upper right-hand side of the screen.
- Choose Articles > Article Layout and on the right-hand side, select the article that you just created.
- On the left-hand side of that screen, you will now see the link which starts with index.php?option=com etc. Copy it.
- NOW open the module where you added the image. Once on that screen, click on the image and then click on the 'Link' icon above to edit the URL.
- Delete the existing URL and paste in the one you just copied, then save.
- Now try it and see if that works. If not, give me a shout.
Hope this helps!
Terry