$(document).ready
(
	function ()
	{
		$('#registration').submit
		(
			function ()
			{
				var submit = true;
				
				if (submit && $('#username').val() == '')
				{
					alert('Zadajte svoju e-mailovú adresu.');
					$('#username').focus();
					submit = false;
				}
				
				if (submit && !checkEmailAddress($('#username').val()))
				{
					alert('Zadaná e-mailová adresa nemá správny formát');
					$('#username').focus();
					submit = false;
				}
				
				if (submit && $('#password').val() == '')
				{
					alert('Zadajte heslo');
					$('#password').focus();
					submit = false;
				}
				
				if (submit && $('#password_again').val() == '')
				{
					alert('Zadajte heslo znovu');
					$('#password_again').focus();
					submit = false;
				}
				
				if
				(
					submit
					&& $('#password').val() != ''
					&& $('#password').val() != $('#password_again').val()
				)
				{
					alert('Zadané heslá niesu rovnaké.');
					$('#password').focus();
					submit = false;
				}
				
				if (submit)
				{
					$('#e_mail').val($('#username').val());
					disableButton('registration_submit');
				}
				
				return submit;
			}
		); 
	}
);

function disableButton(button_id)
{
	$('#' + button_id).attr('disabled', 'disabled');
	$('#' + button_id).html('Čakajte prosím');
	$('#' + button_id).val('Čakajte prosím');
}

function checkEmailAddress(email)
{
	var re = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
	if (!re.test(email))
	{
		return false;
	}
	else
	{
		return true;
	}
}