SortedList sl = new SortedList();
//creating sorted list.
private voidbtnAdd_Click(object sender, EventArgs e)
{
if(txtValue.Text != "" &&txtKey.Text != "")
      {
            sl.Add(txtKey.Text, txtValue.Text);
//adding key and value to sortedlist.
            txtKey.Text= "";
           txtValue.Text = "";
      }
      else
            MessageBox.Show("Text Box Empty");
}