var dropshow=false var currentid function dropdown(el){ if(dropshow){ dropfadeout() }else{ currentid=el el.style.visibility="visible" dropfadein() } } function dropfadein(){ //选单淡入的效果 if(currentid.filters.alpha.opacity<100){ currentid.filters.alpha.opacity+=20 fadetimer=settimeout("dropfadein()",50) }else{ dropshow=true cleartimeout(fadetimer) } } function dropfadeout(){ //选单淡出的效果 if(currentid.filters.alpha.opacity>0){ cleartimeout(fadetimer) currentid.filters.alpha.opacity-=20 fadetimer=settimeout("dropfadeout()",50) }else{ dropshow=false currentid.style.visibility="hidden" } } function dropdownhide(){ if(dropshow){ dropfadeout() dropshow=false } } function hilight(el){ //高亮度显示指标位置 if(dropshow){ for(i=0;i