Adword string breaks website
I use PHP to create many of my websites to help with maintenance, mostly by putting items used by all pages in a site such as header, footer, menus, etc. One of my customers hired another company for marketing. When they sent viewers to the site through the paid ads, there is a string that gets appended to the end of the URL: /?keyword=%2Bkuecker%20%2Blogistics&gclid=CIL55sDS9NMCFdC4wAodApULLQ
The problem is that it "breaks" all of my website pages!
Here is an example:
Without ad string: http://wiseguysconstruction.com/
I've already "fixed" one website by making paths to css, js, etc., relative, and I had use full path URLs in php files I pull into the page with the menu.
How do I avoid this situation in the future?