Fix bug in PHP website

We have a website at www.shoppzz.co.uk.

This offers a list of links, clicking any of which which places the content of a linked external website within an iframe.

Everything works OK when viewed in any version of Internet Explorer (7 upwards) or Safari.

However, in any version of Chrome or Firefox, the following happens: all is perfect unless the user clicks their browser's "Back" button: this works OK if they have visited multiple pages, they are taken backwards through the sequence of pages, but when they reach the 1st page of the sequence **SOMETIMES** they are correctly taken back to our 'index.php' page (the same as if they had clicked the textlink "click here to return to shoppzz.co.uk" in the Orange strip above the iFrame).

The bug is that many times a new Orange strip is added instead saying "click here to return to ctr.html" and each click of the Back button adds another such strip!

Eventually the user might be taken back to www.shoppzz.co.uk/index.php, or a large number of Orange strips might have been added to their screen!

Remember, this behaviour happens in Chrome or Firefox. In IE or Safari the final click of the Back button leaves the user with the 1st page in the iFrame BUT no multiple Orange strips appear, and therefore when they get fed up with pressing the Back button, they can click the textlink in the Orange strip (which is what we wanted them to do!!) and return correctly to www.shoppzz.co.uk/index.php.

We need a fix for this bug!

The problem could possibly be in the file wg.php which our programmer is using to insert the full tracking code into the URL, so I am attaching a copy of that here: