onmouseup、onmousedown、onmouseover、onmouseout分别是什么含意?
<TABLE onmouseup="this.borderColorLight='#ffffff';this.borderColorDark='#000000'" onmousedown="this.borderColorLight='#000000';this.borderColorDark='#ffffff'" onmouseover="this.borderColorLight='#FFFFFF';this.borderColorDark='#000000';" onmouseout="this.borderColorLight='#9FA85F';this.borderColorDark='#9FA85F'" cellSpacing=0 borderColorDark=#9fa85f cellPadding=0
borderColorLight=#9fa85f border=1>