Thread: http serevr

I am making an http server,
when a file is requested the content is shown on the browser,
what I did, I opened the file on the server using:

Code:

fopen(file, "r");

and I send the contet to the client.
the problem is:
when I request an html file, the html code of form in the html file is shown on the browser. but I want to see it as form, I mean the rendered HTML document, what change I need to make to get the html form as I want to get , I mean in form of a 'form' not the code.