If URL Contains 'affiliate1' Then do. For example: www.MyUncleVinny.com?affiliate1

I have a website www.MyUncleVinny.com. We use affiliate codes for financial reporting. For example: www.MyUncleVinny.com?affiliate1

How can I write a simple JavaScript function that will look at the URL and determine if it contains "affiliate1" then do something, like display image1, if the URL contains "affiliate2", then display image2, else display image3.

Thank you SO MUCH in advance.

 

This is not a smart idea, I'd suggset you catch this server side.

 

How do I do this?

 

var aff = location.search.substr(1);

Code (markup):

if aff.length is not zero then it should give you the string.