for asp.net application i didn't use any vb code behind the project

Not at all. You can use any .net supported language in the codebehind. Whether it is vb.net , C# or any other language, it does not matter.

Go through these links to clear your confusion about the code behind model in asp.net

http://support.microsoft.com/kb/303247[^]

http://www.4guysfromrolla.com/ASPScripts/PrintPage.asp?REF=%2Fwebtech%2F100500-1.shtml[^]

http://asp.net-tutorials.com/basics/code-behind/[^]

http://stackoverflow.com/questions/6235164/if-code-behind-not-used-is-aspx-source-code-exposed-to-website-visitors[^]

To clarify the previous solutions, and your understanding of how it works

you must understand that the page your working with is called asp.net markup code. markup code is a combination of HTML and ASP.Net objects, that work together to create your web page. You can preview markup code, to see the results of your markup, and to give you an idea of how your page looks.

One of the things that Microsoft has done, is the ability for a complete asp.net novice to be able to use the design view, drop an asp.net control object onto the markup, and bind it to a data source. Thus producing instant gratification for the novice.

The Code behind page allows those with extensive knowledge of how web pages work, the ability to use pure code to control how the page will control events, or to add handlers to button clicks and so forth.

As you expand your knowledge of how asp.net works, you will end up deleting the bound object in your markup, and use pure code in code behind to load the object data.

Asp.net is quite clever in offering many different avenues of choice (ways to accomplish the task) for an entire range of users, from beginners to the most advanced. It's one of the advantages that separates it from PHP.