var ajaxpdf;

function pdfSwitch(uri)
{
ajaxpdf=null;
if (window.XMLHttpRequest)
  {// code for Firefox, Opera, IE7, etc.
  ajaxpdf=new XMLHttpRequest();
  }
else if (window.ActiveXObject)
  {// code for IE6, IE5
  ajaxpdf=new ActiveXObject("Microsoft.XMLHTTP");
  }
if (ajaxpdf!=null)
  {
  ajaxpdf.onreadystatechange=state_Change_pdf;
  ajaxpdf.open("GET",uri,true);
  ajaxpdf.send(null);
  }
else
  {
  alert("Your browser does not support XMLHTTP.");
  }
}

function state_Change_pdf()
{
if (ajaxpdf.readyState==4)
  {// 4 = "loaded"
  if (ajaxpdf.status==200)
    {// 200 = "OK"
    document.getElementById('viewercontainer').innerHTML=ajaxpdf.responseText;
    }
  else
    {
    alert("Error: " + ajaxpdf.statusText + "?");
    }
  }
}