Calendar control

I'm using the asp.net calendar control inside a div tag. I'm using an <a> tag to popup the calendar control. It was popup is working fine. But I have problem that When I'm clicking on next month in calendar control, the control is disappearing. I want the calendar control to be displayed until i click on specified date.

Sample code:

<A id="anchor" tabIndex=-1 onclick="OnClick()" href="http://forums.asp.net/AddPost.aspx?ForumID=18#" name="anchor"><IMG style="VERTICAL-ALIGN: text-bottom" id="img2" src="../Images/Icon_Calendar1.gif" border=0 /></A>
            <DIV style="DISPLAY: none; POSITION: absolute" id="divCalendar">
            <asp:Calendar id="multiDaySelect" runat="server" OnSelectionChan ...