Making backgroud inactive and blur when a popup panel loads

Making backgroud inactive and blur when a popup panel loads

Hello,
In my project,i am handling popup messages through the asp panel and
div controls.when that popup comes by clicking a button say btnsend,
the background ie the page should become inactive,no button click or
any other functionality should not be done..
The popup panel's css class is popupcurve
.popupcurve
{
    width:45%;
    color: #000000 !important;
    border: 15px solid #cecdbb;
    background-color: #FFFFFF;
    position: fixed !important;
    top: 40%;
    left: 25%;
z-index: 105;
}
The page is like this
<body>
<asp:Button runat="server" ID="butn" Text="Send" />
<asp:Panel ID="PnlConfirmation" runat="server" CssClass="popupcurve"
Visible="false">
<div class="popupcurve_inside" >
<table style="width: 100%;">
<tr>
<td align="center">
<asp:Button ID="btnok" runat="server" Text="OK" />
</td>
</tr>
</table>
</div>
</asp:Panel>
</form>
</body>
Please help me
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