How to get selected listbox item and copy it to a text box control using Java Script.

Just an FYI, this really isn't an ASP.NET question, it is a javascript question and you would probably get better results if you posted in the correct area.  That being said, I think you can accomplish what you want with the following code:

<asp:ListBox ID="MyListBox" runat="server" onchange="ListBoxChanged(this);">
<asp:ListItem Text="1" Value="1" />
<asp:ListItem Text="2" Value="2" />
</asp:ListBox>
<asp:TextBox ID="MyTextBox" runat="server">
<script type="text/javascript">
  function ListBoxChanged(listBox) {
    document.getElementById('<%= MyTextBox.ClientID %>').value = listBox.items[listBox.selectedIndex].text;
  }
</script>

Hi nbove. I can't get your code to work. Your code does not work.

I have been working with various Java Script and can't get it to work with Asp.net listboxes. I think with Asp.net the listbox working with Java Script is different then just your typical listbox control. So I think the question should remain in Asp.net since the Java Script needs to work with the listbox control.

Thanks Champ!