function f_err(el, err_text)
{
	alert(err_text);
	el.focus();
	return false;
}

function email_valid(an_email)
{
  return (an_email.search(/[a-zA-Z0-9_][a-zA-Z0-9_-]*@([a-zA-Z0-9_-]+\.)*[a-zA-Z0-9_-]+/i)>=0);
}

function is_email_valid(an_email)
{
  return email_valid(an_email);
}

function is_empty_str(str)
{
 return (str.toString().replace(/ +/i,"")=="");
}