//calling this function
//	<iframe id="myframe" width="100%" allowtransparency="true" frameborder="0" onload="calcHeight();" scrolling="no" src="forms/contactForm.php"></iframe></p>


//resize iframe http://www.programmingtalk.com/showthread.php?t=25995
function calcHeight()
{
  //find the height of the internal page
  var the_height=
    document.getElementById('myframe').contentWindow.
      document.body.scrollHeight;

  //change the height of the iframe
  document.getElementById('myframe').height=
      the_height + 20;
}