Input string was not in a correct format.

[kplshrm7]

When i write the following lines then i get an error like..
Input string was not in a correct format.

 cmd = new SqlCommand("select Username, Address, City, State, Zip " + "HomePhone, Extension, MobilePhone from Employees" + "where EmployeeID=@EmployeeID", conn);

 cmd.Parameters.Add("@EmployeeID",SqlDbType.Int);
 cmd.Parameters["@EmployeeID"].Value =Convert.ToInt32( DropDownList1.SelectedItem.Value);
        try
        {
            conn.Open();
            reader = cmd.ExecuteReader();
            {
               
                {
     nametextbox.Text = reader["Name"].ToString();
     usernameTextBox.Text = reader["Username"].ToString();
     addressTextBox.Text = reader["Address"].ToString();
     cityTextBox.Text = reader["City"].ToString();
      stateTextBox.Text = reader["State"].ToString();
      zipTextBox.Text = reader["Zip"].ToString();
      homephoneTextBox.Text = reader["HomePhone"].ToString();
      extentionTextBox.Text = reader["Extension"].ToString();
      mobileTextBox.Text = reader["MobilePhone"].ToString();
                }
            }
            reader.Close();
            updateButton.Enabled = true;
        }
       /* catch
        {
            Label1.Text = "Error!!!!!!";
        }*/
        finally
        {

            conn.Close();
        }
    }
}

[NitinSawant]

There is no comma between zip and homephone

Try this:

cmd = new SqlCommand("select Username, Address, City, State, Zip, HomePhone, Extension, MobilePhone from Employees where EmployeeID=@EmployeeID", conn);

Also, have you tried debugging by adding breakpoint on
line 4

MessageBox.Show(DropDownList1.SelectedItem.Value+"");//add this