function checkRegForm(form) {
	if (form.username.value == '') {
		alert('Vyplňte přihlašovací jméno.');
		form.username.focus();
		return false;
	}
	else if (form.pass1.value == '') {
		alert('Vyplňte heslo.');
		form.pass1.focus();
		return false;
	}
	else if (form.pass2.value == '') {
		alert('Zopakujte heslo.');
		form.pass2.focus();
		return false;
	}
	else if (form.pass1.value != form.pass2.value) {
		alert('Hesla se neshodují.');
		form.pass2.focus();
		return false;
	}
	else if (form.name.value == '') {
		alert('Vyplňte jméno.');
		form.name.focus();
		return false;
	}
	else if (form.surname.value == '') {
		alert('Vyplňte příjmení.');
		form.surname.focus();
		return false;
	}
	else if (form.email.value == '') {
		alert('Vyplňte e-mail.');
		form.email.focus();
		return false;
	}
	else if (form.phone.value == '') {
		alert('Vyplňte telefon.');
		form.phone.focus();
		return false;
	}
	else if (form.delivery_name.value == '' ||
			form.delivery_street.value == '' ||
			form.delivery_city.value == '' ||
			form.delivery_code.value == '') {
		alert('Vyplňte doručovací adresu.');
		form.delivery_name.focus();
		return false;
	}

	return true;
}