Import a text file on button click in a web form

I have a web application in which I want to import a text file on button click. To be precise, I want the user to be able to browse to a file location and then copy the file contents to my database.

I cannot use a OpenFileDialog control.I have already tried that because it is a website I am using it in and OpenFileDialog is a windows control.

Does anyone know how to do this using some web technology like Javascript ?