var speed3=25//速度数值越大速度越慢 demo2.innerHTML=demo1.innerHTML function Marquee(){ if(demo2.offsetWidth-demo.scrollLeft<=0) demo.scrollLeft-=demo1.offsetWidth else{ demo.scrollLeft++ } } var MyMar=setInterval(Marquee,speed3) demo.onmouseover=function() {clearInterval(MyMar)} demo.onmouseout=function() {MyMar=setInterval(Marquee,speed3)}