Serializing array of objects

public class Phones{

		[XmlArray ("Phones"), XmlArrayItem(typeof(Models))]
		public ArrayList ArrLstCell = new ArrayList();

public void addObject(Models objModel){
ArrLstCell.items.add(objModel);
}
}

Phones phonesObj=new Phones();
Models Model1=new Models();
Models Model2=new Models();

phonesObj.addObject(Model1);
phonesObj.addObject(Model2);

XmlSerializer serObj = new XmlSerializer (typeof(Phones));

StreamWriter writerObj = new StreamWriter("C:\\PhoneDetails.xml");

serObj.Serialize(writerObj,phonesObj);