function changeLanguage(lang,leftpagename,rightpagename)
{
	document.myform._language.value=lang;
	document.myform.todo.value="changeLanguage";
	document.myform.action='';
	document.myform.submit();
}

function userLogin(err_msg)
{
	if(document.myform.todo.value=="login")
	{
		if(document.myform.u_username.value!='' && document.myform.u_password.value!='')
		{
			document.myform.action="check_login.php";
			document.myform.submit();
		}
		else
		{
			alert(err_msg);	
		}
	}
}