This post explains how to use Balloonpopup Extender control in the asp.net web page to make balloon popup effect. The source page of the code is as follows
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>BalloonPopupExtender control Example</title>
<style
type="text/css">
.c1
{
width:
280px;
height:
240px;
background-color:
Green;
border:
1px black;
padding:
15px;
}
</style>
</head>
<body>
<form
id="form1"
runat="server">
<div>
<asp:ToolkitScriptManager runat="server">
</asp:ToolkitScriptManager>
// panel control is used to make
balloonpopup
<asp:Panel ID="p1" runat="server" CssClass="c1">
This is balloon popup!!</asp:Panel>
// textbox is the target control of the
balloonpopup Extender
<asp:TextBox ID="t1" runat="server"></asp:TextBox>
<asp:BalloonPopupExtender ID="ballpopEx1" runat="server" TargetControlID="t1" BalloonPopupControlID="p1"
Position="BottomRight" BalloonStyle="Cloud" BalloonSize="Small" UseShadow="true"
ScrollBars="Auto" DisplayOnMouseOver="true" DisplayOnFocus="false" DisplayOnClick="true">
</asp:BalloonPopupExtender>
</div>
</form>
</body>
</html>