function centerDiv() {
  var swidth1=window.innerWidth;
  var swidth2=document.body.clientWidth;
  var sdw=900;
  if(swidth1<sdw){swidth1=parseInt(swidth1/2)}
  else {swidth1=parseInt(sdw/2)}
  if(swidth2<sdw){swidth2=parseInt(swidth2/2)}
  else {swidth2=parseInt(sdw/2)}
  if(window.innerHeight){document.getElementById("centered").style.marginLeft=-swidth1 + "px"}
  else if (document.body.clientHeight) {document.getElementById("centered").style.marginLeft=-swidth2 + "px"}
}

function init() {
  if (arguments.callee.done) {return}
  arguments.callee.done = true
  centerDiv()
}

if (window.attachEvent) {
  window.attachEvent("onload", init)
  window.attachEvent("onresize", centerDiv)
}
else if (document.addEventListener) {
  document.addEventListener("DOMContentLoaded", init, false)
  document.addEventListener("onresize", centerDiv, false)
}
window.onload = init
window.onresize = centerDiv