Display forms inside the panel using C# WEB APPLICATION

The reason you may be struggling to find an answer is the terminology you're using. The term Form is generally reserved for Windows applications. When developing web applications use the term Page. Whilst a web page often contains a form, it is a component of the page. When talking about loading content from the server, you're loading a page, not a form.

When content is loaded into a panel from different pages this normally uses a technology called AJAX (Asynchronous Javascript and XML).

There are many panel components available which allow you to asynchronously load content from other pages and display them in your current page. One such component is the UpdatePanel. See the following link for more details:

UpdatePanel Control Overview[^]

If you want to know more about what these components are doing behind the scenes then you need to study writing AJAX code.

Here is a good starting point:

AJAX Introduction[^]

Another way might be to use an iFrame. An iFrame is essentially a browser window inside a browser window and my be suitable for your purposes although are a bit old hat nowadays.

Change content of an iFrame with a Javascript button[^]

Good luck!