title: How do I post a query string to a form field?
body: <p>I have a website with a link that says "Click here to claim your prize" and that link goes to a Sales Force catch all web-to-lead form (that multiple sites use and it has a site ID that I append to the URL so the data goes to the right account)</p>
  
  <p>When a user clicks that link and goes to the form page a string (in this case it's the promo code "my prize") needs to be passed to that form page and placed in the comments form field. </p>
  
  <p>My questions are how is this done, are there any tutorials you could point me to, and is there a better method for accomplishing this? </p>
  
  <p>What I'm trying to avoid is having the link say "Click here to win a free prize! Must enter "My Prize" in the comments" and having the user manually enter the promo code. </p>
  
  <p>Thanks muchly in advance for your help! </p>