Javascript Code For Tracking

I need a piece of code that will allow me to track certain phone numbers coming from a certain ad based on url parameter. Let me explain. Our url would look like this [login to view URL] If ad is = to 1 then display phone number 1 on our landing page. If ad is = to 2 then display phone number 2 in our landing page and so on. We have a list of 30 phone numbers, and they all need to correspond to the correct ad parameter We'll provide the phone numbers, and the idea is to match the phone numbers to the ads 1-30