title: How to create side-by-side record comparison in VisualForce
body: <p>The company recently came upon the need to create a side by side record comparison in Visualforce / Apex.  We routinely have the need to merge leads into contacts.  Previously this was handled in S-Controls; however, recent initiatives and desire to have support for our code on into the future has pushed us to move many of our S-Controls into Visualforce pages and Apex code.</p>
  <p>We are looking to achieve something like this:
  <img src="https://i.stack.imgur.com/3wrf0.png" alt="enter image description here" /></p>
  <p>I have experimented somewhat (with little luck) doing this using the <code>apex:pageBlockTable</code> tag; however, I am not sure how to get two sets of data to render through when it is expecting a single SObject.</p>
  <p>All of the prior code I have to work with was done in S-Controls using JavaScript; and while this code does work now - we need to port this to a VisualForce page.  Obviously I can manually write this using HTML tables...etc but I believe that defeats the purpose of using the stock Salesforce functionality.</p>
  <p>I'm definitely open to alternative methods - as the one i have outlined works, but requires an almost painful amount of coding to make it viable (especially as fields are updated/removed/added in the future).</p>