how to remove this error ??

[PHPycho]

Hello forums!!
I had used the following function(for deleting div elements) and its working properly

function deleteCampaignRow(parentElem, childElem){
var parentObj = document.getElementById(parentElem);
var childObj = document.getElementById(childElem);
parentObj.removeChild(childObj);
}

when the form is submitted , it gives the error "parentObj has no properties".
how to solve the above problem ?
Any Idea ??
Thanks in advance to all of you

[Twey]

function removeElementById(id) {
  var el = document.getElementById(id);
  el.parentNode.removeChild(el);
  return el;
}