title: i have a problem with dropdownLists
body: <p>I have a dictionary that looks like this <code>Dictionary&lt;string,string[]&gt;</code></p>
  
  <p>I also have 2 dropdownlist. I want the second dropdownlist present data depending on what the item from the first dropdropdownlist was chosen.</p>
  
  <p>So i added an event to the second dropdownlist..here is the algorithm:</p>
  
  <pre><code>protected void topicDropDownMenu_SelectedIndexChanged1(object sender, EventArgs e)
  {
      string[] chosenItem;
      chosenItem = null;
      SubTopicDropDownList.ClearSelection();
  
      chosenItem = topic[topicDropDownMenu.SelectedItem.Value];
  
      foreach (string item in chosenItem)
      {
          SubTopicDropDownList.Items.Add(item);
      }
  
  }
  </code></pre>
  
  <p>what actually happens, is that an array of strings is added to the second dropdownlist each time i select an item from the first dropdownlist..</p>
  
  <p>but i want the second dropdownlist to replace its values depending on what was chosen in the first dropdownlist, instead of adding those values to whatever was already placed in the second drop down list</p>