Email must be pre-populated (from InfusionSoft server-side, or via url search parameters). Also store affiliate into cookies if it's there.

infusionsoft-params-inject.html

<script>
    function getParameterByName(name, url) {
        if (!url) url = window.location.href;
        name = name.replace(/[\[\]]/g, "\\$&");
        var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
            results = regex.exec(url);
        if (!results) return null;
        if (!results[2]) return '';
        return decodeURIComponent(results[2].replace(/\+/g, " "));
    };
    function createCookie(name, value, days) {
          var expires;
          if (days) {
              var date = new Date();
              date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
              expires = "; expires=" + date.toGMTString();
          }else{
              expires = "";
          };
          document.cookie = encodeURIComponent(name) + "=" + encodeURIComponent(value) + expires + "; path=/";
    };
    
    jQuery(document).ready(function () {
      var inf_contact_key = getParameterByName('inf_contact_key');
      var inf_field_Email = getParameterByName('inf_field_Email');
      
      var firstName= jQuery('#firstName');
      var emailAddress= jQuery('#emailAddress');
      var purchaseButton= jQuery('.complete-purchase');
      
      if (inf_contact_key) {
          // lock down fields since InfusionSoft pre-populates.
          if (firstName.val()!=='') {
              firstName.prop('disabled', true);
          };
          if (emailAddress.val()!=='') {
              emailAddress.prop('disabled', true);
          }else{
              //edge case: infusionsoft does not have email injected
              //
          };
      }else if(inf_field_Email){
          emailAddress.val(inf_field_Email);
          emailAddress.prop('disabled', true);
      }else{
          // No email or infusionsoft data found in URL. 
          // Possibly done via cookies + server side render
          if (emailAddress.val()!==''){
              emailAddress.prop('disabled', true);
          }else{
              //Re-direct back to dashboard = off
          };
      };
                
      var params= window.location.search;
      jQuery("a[href='https://ee289.infusionsoft.com/app/orderForms/f0791acc-a9e8-4796-8bad-d6eae1acca8f']")
        .attr('href', 'https://ee289.infusionsoft.com/app/orderForms/f0791acc-a9e8-4796-8bad-d6eae1acca8f'+params);
      jQuery("a[href='https://ee289.infusionsoft.com/app/orderForms/e1da5d9f-8731-479a-80ab-dd714abb66e0']")
        .attr('href', 'https://ee289.infusionsoft.com/app/orderForms/e1da5d9f-8731-479a-80ab-dd714abb66e0'+params);

      //if affiliate in url, set to cookies
      var affiliate = getParameterByName('affiliate');
      if(affiliate){
      	createCookie('affiliate', affiliate, 30);
      };
  });
</script>