function capLock(e){
 kc = e.keyCode?e.keyCode:e.which;
 sk = e.shiftKey?e.shiftKey: ( (kc == 16)?true:false); 
 if(((kc >= 65 && kc <= 90) && !sk)||((kc >= 97 && kc <= 122) && sk)) {
  document.getElementById("divMayus").style.visibility = "visible";
 }
 else {
  document.getElementById("divMayus").style.visibility = "hidden";
 }

  var theEvent = e || window.event;
  var key = theEvent.keyCode || theEvent.which;
  key = String.fromCharCode( key );
  var regex = /[&]/;
  if( regex.test(key) ) {
    theEvent.returnValue = false;
    if(theEvent.preventDefault) {
      theEvent.preventDefault();
    }
  }  
}