index3 I want to create menu style given in image when i clicked menu it opens its content, but when i clicked to 2nd menu it closes previously opened menu and open 2nd menu. please see image so you get perfect idea what i want to say...if you have samole code then please attach it

Have you attempted to write any code that we can help you with?

yes with asp:panel tag but i dont get desired output

you can either use some of the controls that come with the ajax toolkit on the web site, asp.net, or just develop this using HTML and JavaScript. Without the help of the asp.net controls, this looks like you can build it using divs stacked on each other, then with the help of JavaScript and jQuery, have the divs perform a slidetoggle effect.