function navigatorIsIE7() {
	agent = navigator.userAgent.toLowerCase();
	this.major = parseInt(navigator.appVersion);
	this.minor = parseFloat(navigator.appVersion);
	this.ie = ((agent.indexOf("msie") != -1) && (agent.indexOf("opera") == -1));

	this.ie7 = (this.ie && (this.major == 4) && (agent.indexOf("msie 7") != -1));

	if (this.ie7) {
		return true;
	}
	else {
		return false;
	}
}


function disableRightClick(e)
{
  var message = "Boton derecho no soportado";
  
  if(!document.rightClickDisabled) // initialize
  {
    if(document.layers) 
    {
      document.captureEvents(Event.MOUSEDOWN);
      document.onmousedown = disableRightClick;
    }
    else document.oncontextmenu = disableRightClick;
    return document.rightClickDisabled = true;
  }
  if(document.layers || (document.getElementById && !document.all))
  {
    if (e.which==2||e.which==3)
    {
      alert(message);
      return false;
    }
  }
  else
  {
	if (!navigatorIsIE7()) {
		alert(message);
	}
	return false;
  }
}
disableRightClick();