How to launch a background task from a web page

I have some long running scripts which I need to launch from a web page and have them run in the background, but which should not cause the web page to wait until the script finishes. Reading the manual on the backtick and exec() operators seems to imply that the PHP function will be suspended until the script finishes, which is not what I want. Is this possible in PHP? -- Tony Marston http://www.tonymarston.net http://www.radicore.org