function validateLogin()
{
	var error = 0;

	if(document.getElementById("username").value == "")
	{
		error++;
		alert("You have to enter a username");
	}	
	
	if(document.getElementById("password").value == "")
	{
		error++;
		alert("You have to enter your password");
	}
	
	
	if(error == 0)
	{
		document.getElementById("login_form").submit();
	}
}