function smf_login(user, pass, length)
	{
	//Callback function must be provided: smf_interface_refresh_login
	//Needs Functions: 
	// - create_XMLHttpRequest()
		if (user == "" )
		{
			alert("Please enter your username!");
		}
		else
			if (pass == "" )
			{
				alert("Please enter your password!");
			}
			else
				{
				create_XMLHttpRequest();
				http_request.onreadystatechange = smf_interface_refresh_login ;
				http_request.open('POST', 'http://www.global-flat.com/includes/smf_bridge/user_login.php', true);
				http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	    		var param_list = 'user='+user+'&pass='+pass+'&length='+length;		
				http_request.send(param_list);
			}
	}
	
	function smf_is_authenticated()
	{
	//Callback function must be provided: smf_interface_refresh_authenticated
	//Needs Function: create_XMLHttpRequest()
		create_XMLHttpRequest();
		http_request.onreadystatechange = smf_interface_refresh_authenticated ;
		http_request.open('GET', 'http://www.global-flat.com/bikeconf2/loginCheck.php', true);
		http_request.send(null);
	}