making text files

i have one text box and submit button in the form. i wnat to ceonvert the text when posted into HTML. although i have made this but how will i save this HTML in the text file under my folder i ma not able to save the converted text into HTML in the file which i will be able to link to that file from the program itself
eg
it will create the html file and svae the contents and i will be ale to view the link on next page such as "name.htm" as soon as the file gets created and clicking the file will open a new window with the contents of that text box
pls hepl me if anybobe can hep .i will hae to shoe this work and if anybody will hepl mne thru coding then it wiill be fine as i have to show by today