remove webusercontrol's corners when rounding corners

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C#

ASP.NET

Hi I have this web user control, and there are white corners in my control when I use border-radius:10px in my css. My control are showing they have rounded corners especially if i put border on it, but there also unwanted corners left underneath those rounded corners. Any idea how to remove those?

here is the script of my user control:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="ucClaimsMsgBox.ascx.cs" Inherits="iLIFE.Group.Claims.ucClaimsMsgBox" %>
<link href="/C/>
<link href="/C/>

<div class="ucInfoBoxC>
    <table class="outline"  runat="server" id="tblInfobox">
        <tr>
            <td style="width:80px; text-align:center"><asp:Image runat="server" ID="imgIcon" ImageUrl="~/Images/icoQuestion.png" Width="70" Height="70" /></td>
            <td>
                <table>    
                    <tr><td><asp:Label runat="server" ID="lblMsgTitle" Text="Title" CssClass="msgTitle" ></asp:Label> </td></tr>
                    <tr><td>
                        <div class="msgC><asp:Label runat="server" ID="lblMsgContent" Text="The quick brown fox jumps over the lazy dogThe quick brown fox jumps over the lazy dogThe quick brown fox jumps over the lazy dogThe quick brown fox jumps over the lazy dogThe quick brown fox "></asp:Label></div>
                    </td></tr>
                    <tr><td style="text-align:right">
                        <asp:Button runat="server" ID="btnC" Text="CLICK 3" CssClass="btn btn-info btns_text" />
                        <asp:Button runat="server" ID="btnB" Text="CLICK 2" CssClass="btn btn-info btns_text" />
                        <asp:Button runat="server" ID="btnA" Text="CLICK 1" CssClass="btn btn-info btns_text"  />
                    </td></tr>
                </table>
            </td>
        </tr>
    </table>
</div>

the css i use:

.ucInfoBoxControl
{
    font-family:Arial,sans-serif;
    font-size:12px;
    background-color:white;
}
    .ucInfoBoxControl .outline
    {
        border:2px solid #C0C0C0;
        border-radius:10px;
        box-shadow: 0 8px 6px -8px black;
    }

.msgTitle
{
    font-size:14px;
    font-weight:bolder;
    letter-spacing:1px;
}

.msgContent
{
    height:50px;
    width:400px;
    word-wrap:break-word;
    overflow:auto;
}