// JavaScript Document
function validar(){
  if (document.getElementById("login").value.length == 0) {
	alert("You must enter a login");
	document.Frm.login.focus();
	return false;
  }
  else if(document.getElementById("contrasena").value.length == 0) {
	alert("You must enter a password");
	document.Frm.contrasena.focus();
	return false;
  }
  else{
	  document.getElementById("Frm").submit();
  }
}