Show Hide DIV on ASP.Net DropDownList change in JavaScript

Sir Need help

on dropdown value change need to show / hide div

please guide

<tr>
    <td style="width: 100px">Voucher Type
        <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server"
        ControlToValidate="cboVoucherType" Display="Dynamic" InitialValue="0"
        ErrorMessage="*" ValidationGroup="btnAddDetail">
    </asp:RequiredFieldValidator>
        <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server"
            ControlToValidate="cboVoucherType" Display="Dynamic" InitialValue="0"
            ErrorMessage="*" ValidationGroup="btnSubmit">
        </asp:RequiredFieldValidator>
    </td>
    <td>
        <asp:DropDownList ID="cboVoucherType" runat="server" CssClass="chzn-select" Width="200px"></asp:DropDownList>
    </td>
</tr>

<script type="text/javascript">
    function change() {
        var DropdownList = document.getElementById('<%=cboVoucherType.ClientID%>');
        var SelectedIndex = DropdownList.selectedIndex;
        var divEntrySingle = document.getElementById('divEntrySingle');
        var divEntryMultipal = document.getElementById('divEntryMultipal');
         
        if (SelectedIndex == 1) {
            divEntrySingle.style.display = "none";
            divEntryMultipal.style.display = "block";
        }
        else {
            divEntrySingle.style.display = "block";
            divEntryMultipal.style.display = "none";
        }
    }
</script>