title: Javascript: Can‘t get document.getelementbyid to work
body: <p>I found many questions concerning form elements that are null but I simply can‘t get this to work.</p>
  
  <p>It works in every browser but when it‘s embedded in Wordpress it stops working in Firefox.
  The Firefox-Console says I should use document.getelementbyid but in every way I try it, Firefox says the form is null or that "myform is not defined".</p>