Web Forms

I have got a unmanaged Web Application and i want to change it into managed web application manually So there raised the need of creating a web form application dynamcially So i wrote the HTML code in a file a saved with aspx ext all the code including code related to presentation and code in the code behind file i wrote it in a single file can i do that ? If so can i add this page/file to a solution ans execute safely? Or if myapproach is wrong how can i create a web form dynamically and controls (manage code or script like event handling /business logic ) without creating a solution please help me out Thank you