replacing chars in input

Hi, all -- I would like to make things easier for my users and replace all of the garbage characters `'";:~!@#$%^&*()[]{}<>/?\|+= plus white space (\s) with underscores in the input. I am, however, having trouble getting my regexp to work. I can comfortably do $i = preg_replace("/[\s]/","_",$i) ; but trying to add other chars doesn't do a thing. I want to end up with A-Za-z0-9_- (letters, numbers, underscore and dash). If there isn't a handy character class waiting for me, what must I do to get those chars replaced? TIA & HAND :-D -- David T-G * There is too much animal courage in (play) davidtg@justpickone.org * society and not sufficient moral courage. (work) davidtgwork@justpickone.org -- Mary Baker Eddy, "Science and Health" http://justpickone.org/davidtg/ Shpx gur Pbzzhavpngvbaf Qrprapl Npg!