JS: node.insertBefore

[DGL-luke]

Hallo, habe folgendes Javascript:

Code:

//input field generator

function addField(pre,post,formtable,before)
{
  var node = document.createElement("tr");
  
  var td = node.appendChild(document.createElement("td"));
  
  var input = td.appendChild(document.createElement("input"));
  
  input.setAttribute("type", "text");
  input.setAttribute("name", "usernames[]");

  var cb = td.appendChild(document.createElement("input"));
  
  cb.setAttribute("type", "checkbox");
  cb.setAttribute("name", "encryptmd5[]");

  td.appendChild(document.createTextNode(" MD5 verschlüsseln"));

  if (pre != null)
    formtable.appendChild(pre);
  if (before != null)
    formtable.insertBefore(node,before); //<--hier
  else
    formtable.appendChild(node);
  if (post != null)
    formtable.appendChild(post);
}

ganz unten, bei der markierten anweisung kommt eine exception:

Zitat:

Fehler: uncaught exception: [Exception... "Node was not found" code: "8" nsresult: "0x80530008 (NS_ERROR_DOM_NOT_FOUND_ERR)" location: "file:///E:/WEB/xampp/htdocs/develop/htusers_generator/htusers.js Line: 24"]

Das HTML sieht so aus:

Code:

<form action="htuser.php">
  <table id="formtable">
    <tr id="before"><td><input type="reset" value="Reset"><input type="submit" value="Abschicken"></td></tr>
  </table>
</form>

ich hole mit das before vorher:

Code:

function Init()
    {
      var formtable = document.getElementById("formtable");
      var before = document.getElementById("before");
      addField(null,null,formtable,before);
    }