var printDivName;
var printStyle; 

var printOff = 0;
var printOn = 1;
var screenOn = 2;
var screenOff = 3;
var controlStyle = new Array('printOff', 'printOn', 'screenOn', 'screenOff');


function window.onbeforeprint(){
  if (!printDivName && !screenDivName)return false;
  var obj1 = document.all.item(screenDivName);
  var obj2 = document.all.item(printDivName);
  
  obj1.className = controlStyle [printOff];
  obj2.className = controlStyle [printOn];
};

function window.onafterprint(){
  if (!printDivName && !screenDivName)return false;
  var obj1 = document.all.item(screenDivName);
  var obj2 = document.all.item(printDivName);
  
  d1.className = controlStyle [screenOn];
  d2.className = controlStyle [screenOff];
};