function cambia_iframe(a, w)
{
   var xx = document.getElementById('miframe');
   xx.src = a;   
   if (w != "")
	xx.width = w;
}

function ajustar(){
  var frm = document.getElementById('miframe');
  if ( frm.contentDocument ) { // DOM
    if (frm.contentDocument.getElementById('id_body'))
    {
        var bd = frm.contentDocument.getElementById('id_body');
        var naltura = bd.offsetHeight;
        document.getElementById('miframe').height = naltura;    // Cambio altura de iframe
    }
  }
  else if (frm.contentWindow) { // IE6 win
    if (frm.contentWindow.document.getElementById('id_body'))
    {
        var bd = frm.contentWindow.document.getElementById('id_body');
        var naltura = bd.offsetHeight;
        document.getElementById('miframe').height = naltura;    // Cambio altura de iframe
    }
  }
}