How do I make this web service work?
<p>I am a new developer and trying to develop a web service in C# by following <a href="http://dotnetguts.blogspot.com/2007/09/all-about-web-service-in-net.html" rel="nofollow">this tutorial</a>. I did everything as explained in that tutorial, however, I did not get any data from the Northwind database and I got the following page when I pressed the Invoke button:
<img src="http://i.stack.imgur.com/VLvfT.png" alt="enter image description here"> </p>

<p>As you will see in the tutorial, I did not add the ConnectionString to the web.config file. Should I do that? </p>

<p>My code:</p>

<pre><code>public class WSGetCustomerCountryWise : System.Web.Services.WebService
{
    public WSGetCustomerCountryWise()
    {

        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }

    [WebMethod(Description = "It will generate Customer List, CountryWise")]
    public System.Xml.XmlElement
        GetCustomerCountryWise(string sCountry)
    {
        string sConn = ConfigurationManager.ConnectionStrings["connStr"].ToString();
        string sSQL = "select CustomerId, CompanyName, ContactTitle, City from Customers where country = '"+sCountry+"'";
        SqlConnection connCustomer = new SqlConnection(sConn);
        DataSet dsCustomer = new DataSet();
        SqlDataAdapter sda = new SqlDataAdapter(sSQL, sConn);
        sda.Fill(dsCustomer);

        System.Xml.XmlDataDocument xdd = new System.Xml.XmlDataDocument(dsCustomer);
        System.Xml.XmlElement docElem = xdd.DocumentElement;
        return docElem;

    }

}
</code></pre>
