/* Code below is pure JS (without framework) */

function printBtn(){
  if (document.getElementById) {
    if (document.getElementById('printBtn')) {
      btn = document.getElementById('printBtn');
      btn.innerHTML = '<a href="javascript:window.print();">' + btn.innerHTML + '</a>';
    }
  }
}

function addLoadEvent(func) { 
   var prev_onload = window.onload; 
   if (typeof window.onload != 'function') { 
      window.onload = func; 
   } 
   else { 
      window.onload = function() { 
         prev_onload(); 
         func(); 
      } 
   } 
}

addLoadEvent(function() {
  printBtn();
});