Pass DataSet into XML C#

Here's a simple code of retrieving data from a Database into XML Document:

using System.Xml;
using System.Configuration;
using System.Data.SqlClient;

protected XmlDocument GetXML(int input)
{
const string strStoredProc = "SP";
const string ROOTNODE = "ROOT";
const string NODENAME = "NODE";
string sqlConnectionString = GetConnectionString();
SqlConnection sqlConnection = new SqlConnection(sqlConnectionString);
SqlCommand sqlCommand;
XmlDataDocument xmlDoc = null;
try
{
sqlCommand = new SqlCommand(strStoredProc, sqlConnection);


sqlCommand.CommandType = CommandType.StoredProcedure;

sqlCommand.Parameters.Add("@INPUT", SqlDbType.Int);
sqlCommand.Parameters["@IN_Year"].Value = Int32.Parse(input);

sqlConnection.Open();

DataSet ds = new DataSet();
ds.DataSetName = ROOTNODE;

ds.Load(sqlCommand.ExecuteReader(), LoadOption.OverwriteChanges, NODENAME);
xmlDoc = new XmlDataDocument(ds);
}
catch (Exception ex)
{

}
finally
{
sqlConnection.Dispose();
}
return xmlDoc;

}