xml的问题
提交一个XML，但提示说XML没根元素。郁闷。大家看看

XmlDocument fsxml = new XmlDocument();
XmlDeclaration fssmxml;
fssmxml=fsxml.CreateXmlDeclaration( "1.0 ", "gb2312 ", "yes ");
fsxml.AppendChild(fssmxml);

XmlElement sxrmxx =fsxml.CreateElement( "SXRMXX ");
XmlNode s =fsxml.SelectSingleNode( "SXRMXX ");
XmlElement login =fsxml.CreateElement( "LOGIN ");

XmlElement username =fsxml.CreateElement( "USERNAME ");
username.InnerText= "103005 ";
login.AppendChild(username);

XmlElement password = fsxml.CreateElement( "PASSWORD ");
password.InnerText = "103005 ";
login.AppendChild(password);

sxrmxx.AppendChild(login);

//XmlNode sxrmxx2 =fsxml.SelectSingleNode( "SXRMXX ");
XmlElement operation =fsxml.CreateElement( "OPERATION ");
operation.InnerText= "1 ";
sxrmxx.AppendChild(operation)；

XmlElement unitinfo =fsxml.CreateElement( "UNITINFO ");

XmlElement xzqh = fsxml.CreateElement( "XZQH ");
xzqh.InnerText= "103005 ";
unitinfo.AppendChild(xzqh);


XmlElement dwbm = fsxml.CreateElement( "DWBM ");
dwbm.InnerText= "440100 ";
unitinfo.AppendChild(dwbm);
sxrmxx.AppendChild(unitinfo);//添加unitinfo

fsxml.Save(Server.MapPath(strFileName));

[解决办法]
最后加上 fsxml.AppendChild(sxrmxx);