public override void Save(XmlWriter xmlw)
{
xmlw.WriteStartElement("WallTile");
if (_illusion) xmlw.WriteAttributeString("Illusion", _illusion.ToString());
if (_illusionVisible) xmlw.WriteAttributeString("Illusionvisible", _illusionVisible.ToString());
if (_health > -1) xmlw.WriteAttributeString("Health", _health.ToString());
if (_type != Backend.WallType.Normal) xmlw.WriteAttributeString("Type", _type.ToString());
if (!_enabled) xmlw.WriteAttributeString("Enabled", _enabled.ToString());
xmlw.WriteEndElement();
}