Hello, there. First of all BACKUP the specific file (/includes/header.php)!
If you would like to see this contribution in action, please refer to http://apa3.co.uk and add an item to the shopping cart. Watch the bread crumb.
Well, now let us do that 2-minutes-work to include this nice contribution:
1. Locate your header.php in /includes/header.php (on catalog side) and open it with an editor.
2. Find (about lines 45 to 47 - depending on, how many lines of code you already added)
and DIRECTLY BELOW add THIS CODE:
3. You may change the color (by default it is YELLOW) as you like. Therefor you either can alter to *blue*, *red* or even *#FFFFFF* or other HTML color codes. To change the text/alert, simply use your language instead of *WARENWERT IM KORB*.
4. Save your changes and upload to your server.
5. Refresh your web (press F5 on you keyboard) and try the new add-on by adding at least one article to your shopping cart.
6. Have fun with that neet little code pile.
We only testet with v2.3, but suppost to work with prior versions too. SCREENSHOT included.