title: Salesforce Javascript OnClick
body: <p>I'm trying to do something that should be very basic in SalseForce. I just need a button to run a small piece of javascript. It's throwing the following error at the moment "Invalid assignment left hand side error". Any help would be greatly appreciated.</p>
  
  <pre><code>if (  {!Contact.MailingPostalCode} =  'SC') {window.open('http://www.google.com','mywindow'); }
  
  if (  {!Contact.MailingPostalCode}  =  'FL')  {window.open('http://www.yahoo.com','mywindow');  
  }
  </code></pre>
  
  <p>Thanks</p>