function Validacion(theForm) {
  //print lo erróneo
  var error = false
  var str = ""
  if (theForm.name.value == "")     {str = str + "\n  - the 'Name' field is empty"; error = true;}
  if (theForm.address.value == "")  {str = str + "\n  - the 'Address' field is empty"; error = true;}
  if (theForm.email.value == "" || isEmail(theForm.email.value) == false )  {str = str + "\n  - 'E-mail' is empty or is not correct"; error = true;}
  if (theForm.phone.value == "" || isNumber(theForm.phone.value) == false ) {str = str + "\n  - 'Phone number' is empty or is not correct"; error = true;}
  //si error --> focus en el primer error y salgo
  if (error==true) {
    alert("Error in the following fields:"+str);	
  	return (false);
  }
  return (true);
}