public void ReplacedatetimeAt(datetimeType newValue, int index)
{
ReplaceDomChildAt(NodeType.Element, "http://www.imsglobal.org/xsd/imsmd_rootv1p2p1", "datetime", index, newValue.ToString());
}
public void Adddatetime(datetimeType newValue)
{
AppendDomChild(NodeType.Element, "http://www.imsglobal.org/xsd/imsmd_rootv1p2p1", "datetime", newValue.ToString());
}