Page1: Javascript to set cookie via GTM, and Page2: edit a DOM if cookie is set

We have a website and on that website is a home page. The home page shows a phone number like this: <a href="tel:1810912012" title="Call Us on 1810 912 012">1810 912 012</a> If a customer logs into the website, then we need javascript that does this: Set 3 month cookie: PPX_Exist_Cookie=”dd/mm/yy hh:mm:sss” Then on the home page, we need javascript to check for the existance of cookie PPX_Exist_Cookie and if it exists, then edit the DOM to this (note this is a differnet phone number). <a href="tel:1810915015" title="Call Us on 1810 915 015">1810 915 015</a> This version of jquery is available on these pages: [login to view URL] So the deliverables are: - Javascript snippet to set the cookie - Javascript snippet to check the cookie and edit the DOM if the cookie is found