Table border lines showing over panels ASP NET

Question

I'm currently trying to figure out what the hell is happening, when I pop up a panel(date picker) when clicking a textbox, I get the table borders overlapping on the panel.

I'm pretty new to ASP NET / c# etc but from what I can see there is no 'show on top' or 'force top' option within the panel properties.

Thank you very much in advanced, pic of the issue and code for that section below as well.

EDIT: it also only seems to be the 'dates' that have the lines, as you can see Mon / tues and the month picker don't seem to be affected.

I've now set EVERY style to z-index: -1; other than the panel which is z-index 99999 but still not working :(

Issue still happening but using the following code now: Head

<style type="text/css"> #txtresumedate_PopupControlExtender { z-index:99999; } Also tried and forced the cssstyle onto the panel: <style type="text/css"> .panel { z-index:99999; }

Body:

            `<tr>
            <td class="style9">
                Likely resumption date?</td>
            <td class="style12">
                <asp:TextBox ID="txtresumedate" runat="server" Width="100%"></asp:TextBox>
                <ajax:PopupControlExtender ID="txtresumedate_PopupControlExtender" 
                    runat="server" DynamicServicePath="" Enabled="True" ExtenderControlID="" 
                    PopupControlID="Panel1" Position="Bottom" TargetControlID="txtresumedate">
                </ajax:PopupControlExtender>
                <asp:Panel ID="Panel1" runat="server" Width="400px"  
                    BorderStyle="Double" >
                    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                        <ContentTemplate>
                            <asp:Calendar ID="Calendar1" runat="server" 
                                onselectionchanged="Calendar1_SelectionChanged" Width="200px">
                            </asp:Calendar>
                        </ContentTemplate>
                    </asp:UpdatePanel> 
                </asp:Panel>
            </td>
        </tr>`

Answer 1

The following should solve you problem:

#Panel1 {
    background-color:#ffffff;
    z-index:9999;
}

Answer 2

Try this - use z-index

<style type="text/css" />
   #txtresumedate_PopupControlExtender
   {
         z-index:99999; // make sure this should be greater then table's z-index
   }
</style>