check current url PHP : How I can identify in PHP if my current URL contain this text **special_offer=12**.
for example if my domain URL is http://www.example.com/newproducts.html?special_offer=12 then echo something;

 or the domain can be http://example.com/all-products.html?cat=93&special_offer=12

Always this text will be same "special_offer=12"

thank you