title: The ConnectionString property has not been initialized
body: <p>My connection string is placed in web.config as follows.</p>
  
  <pre><code>&lt;connectionStrings&gt;
     &lt;add name="empcon" connectionString="Persist Security Info=False;User ID=sa;Password=abc;Initial Catalog=db5pmto8pm;Data Source=SOWMYA-3BBF60D0\SOWMYA" /&gt;
  &lt;/connectionStrings&gt;
  </code></pre>
  
  <p>and the code of program is...</p>
  
  <pre><code>public partial class empoperations : System.Web.UI.Page
  {
  
      string constr = null;
  
      protected void Page_Load(object sender, EventArgs e)
  
      {
          ConfigurationManager.ConnectionStrings["empcon"].ToString();
           if (!this.IsPostBack)
          {
              fillemps();
          }
      }
      public void fillemps()
      {
          dlstemps.Items.Clear();
          SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["empcon"].ConnectionString);
          con.ConnectionString = constr;
          SqlCommand cmd = new SqlCommand();
          cmd.CommandText = "select * from emp";
          cmd.Connection = con;
          SqlDataReader reader;
          try
          {
              con.Open();
              reader = cmd.ExecuteReader();
              while (reader.Read())
              {
                  ListItem lt = new ListItem();
                  lt.Text = reader["ename"].ToString();
                  lt.Value = reader["empno"].ToString();
                  dlstemps.Items.Add(lt);
              }
              reader.Close();
          }
          catch (Exception er)
          {
              lblerror.Text = er.Message;
          }
          finally
          {
              con.Close();
          }        
  </code></pre>
  
  <p>i am totally new to programing....</p>
  
  <p>i am able to run this application with er.message in label control as "the connection string property has not been initialized"</p>
  
  <p>i need to retrieve the list of names of employees from the emp table in database into the dropdownlist and show them to the user...</p>
  
  <p>can any one please fix it...</p>