random password generator?

Hi,

I would like a "gererate password" button that fills a filed with an alphanumeric passwrod of 8 characters or so.  Wildcard characters would be good as well.  Can anyone help me with a script that can create random passwords?  Also - I understand it may not be truly random as a response duplicated could be created every 1,233,432 times or whatever and thats OK  It would be random enought.  Thanks much.