How to move items between listbox

Question

I have a 3 Listboxes, The first one gets the data from server and on click of the first listbox, there is an "ON Selection" change event to populate listbox 2. Autopostback is made to true for the first list box.

I then need to move items from Listbox 2 to listbox 3 through buttons. The issue i am facing is.

After i move the items from listbox 2 to 3. I then go and click on listbox 1, the page refreshes and the items in listbox 3 disappear.

Please let me know, on how to fix this issue.

Thank you

Please find the code below..

 <asp:ListBox ID="lstdata" runat="server" Style="margin-top: 0px" Rows="20" AutoPostBack="true"
                        OnSelectedIndexChanged="lstdata_SelectedIndexChanged1" SelectionMode="Multiple"
                        EnableViewState="true" Height="318px" Width="199px"></asp:ListBox>
                </td>
                <td class="style2" rowspan="6">Metric Options
                    <asp:ListBox ID="lstdata2" runat="server" Rows="20" Width="184px" 
                        SelectionMode="Multiple"></asp:ListBox>
                </td>

        <td class="style2">
            &nbsp;</td>
        <td class="style2" rowspan="6">Selected Metric
            <asp:ListBox ID="ListBox1" runat="server" AutoPostBack="false" Rows="20" 
                SelectionMode="Multiple" Height="317px" style="margin-top: 0px" 
                Width="149px">
            </asp:ListBox>

        </td>