var oPop=null;
function openPopUp(theURL,winName,features) { //v2.0
  if(oPop) oPop.focus();
  oPop=window.open(theURL,winName,features);
} 

function focusPop() { 
  var oBody=document.getElementsByTagName("body")[0];
  if(oBody.className=="bodypopup") {
    window.focus();
    window.onblur=window.close;
  }
}

window.onload=focusPop;