string connStr = "database=Northwind;Data Source=.;User id=sa;pwd=123123"; 
using ...(SqlConnection conn = new SqlConnection(connStr)) 
...{ 
SqlCommand command = new SqlCommand("select * from Customers", conn); conn.Open(); DataSet ds = new DataSet(); ds.DataSetName = "Customers"; ds.Load(command.ExecuteReader(), LoadOption.OverwriteChanges, "Customer"); Response.ContentType = "text/xml"; ds.WriteXml(Response.OutputStream); }