Hi In fact, the problem is that Safari seems to not support self-reference in javascript class. The two last variables in ImagePreload.prototype.OnLoad are marked as "undefined". For those who wants to debug in Safari with MacOS, type "defaults write com.apple.Safari IncludeDebugMenu 1" on a terminal and then restart Safari. A "debug" menu will be present on the top of the screen. I think it's a safari bug, but it should exists a workaround. Regards, Riton