DHTML was a horrible buggy inaccessible mess for anything more than extremely basic stuff. No design tools, and they didn't perform nearly as well as Flash. And

DHTML was a horrible buggy inaccessible mess for anything more than extremely basic stuff. No design tools, and they didn't perform nearly as well as Flash. And sound? I highly doubt that in 1998 there was any capability for syncing sound files to animations outside of browser plugins like Flash, or shockwave or other lesser known plugins.