how to insert html content Permentantly from c#

Hi, I want when i click the button This code generated in Html but not on loading event only,i want to store it in the Html and can remove it if i want,i want to insert this code Div Control in html <li value="1"> <img src="photos/Dock.jpg" width="80" height="60" alt="" onclick="document.getElementById('detailimg').src=this.src;" /></li> and that all my html code div id="thumbarea" style="z-index: 100; left: 15px; top: 160px; background-color: gainsboro;" runat="server"> <ul id="thumbs"> <li value="1"> <img src="photos/Dock.jpg" width="80" height="60" alt="" onclick="document.getElementById('detailimg').src=this.src;" /></li> <li value="2&qu ...