I don't see any kind of error. (using Mac os x).
It's said that to bring up mysql on mac os you go to the Terminal (the Mac commandline) and just type in "mysql -h -u -p" and fill in the required fields after the prompt. After that the prompt should change to "mysql". But when trying it sais something like "mysql is not a recognized command", or in that direction. Even if no password is supplied.
When trying to connect via php, with mysql_connect($username, $localhost,''), the page goes blank. That's why it's hard to identify the problem.
Maybe mysql just needs to be reinstalled. I just don't want to clutter up the directories with more dmg or exe files without knowing which one of them will be obsolete, or having to remember just that. Perhaps, if you re-install mysql it will overwrite any previous installation? If so, that'd be nice. Because it would be easier than trying to find out about the details of the problem .