function check_reservation(form) {
	if(form.name.value == '' || form.name.value.charAt(0) == ' ') {
		alert('Please, enter your name!\n(First character must be no empty)');
		form.name.focus();
		return false;
	} 
	
	if(form.mail.value == '' || form.mail.value.charAt(0) == ' ') {
		alert('Please, enter your e-mail!\n(First character must be no empty)');
		form.mail.focus();
		return false;
	} else {
		if(form.mail.value.length < 7) {
			alert('Your e-mail address must have at least 7 Characters!');
			form.mail.focus();				
			return false;
		} else {
			if(form.mail.value.indexOf('@') < 0) {
				alert('Your e-mail address must consist the character - @!');
				form.mail.focus();				
				return false;
			} else {
				if(form.mail.value.indexOf(' ') > 0) {
					alert('Your e-mail address must not consist the empty character!');						
					form.mail.focus();						
					return false;
				}
			}
		}
	}
	
	return true
}