filename for output

Is there a way to dynamically specify the filename to a php script's output?

Here's what I'm trying to do. I'm writing a php script to dynamically generate postscript files based on form input. Is there a way to specify the name of the file the client receives, so that the downloaded postscript file doesn't have the same name as the script?

I know I can print a Content-type header so that the client knows it's postscript. What I want to do is name the output file, according to values the user has entered in the form.

Thanks