<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title> Uniform motion demonstration </title><style type="text/css"><!--#div1 {width:1px;height:200px;background-color: black;position:absolute;left:100px;top:70px;float:left}#div1 span {position:absolute;top:-15px}#div2 {width:1px;height:200px;background-color:midnightblue;position:absolute;left:800px;top:70px;float: left}#div2 span {position:absolute;top:-15px}#div3 {width:1px;height:200px;background-color:fuchsia;position:absolute;left:300px;top:70px;float: left}#div3 span {position:absolute;top:-15px}#div4 {width:1px;height:200px;background-color:darkmagenta;position:absolute;left:500px;top:70px;float: left}#div4 span {position:absolute;top:-15px}#grap {width:200px;height:200px;background:red;position:absolute;left:300px;top:74px;float: left;}input {width:100px;margin-left: 90px;}--></style><script type="text/javascript">var timeIdfunction startMove(target){var oDiv=document.getElementById('grap')clearInterval(timeId); //This place is to prevent the phenomenon of multi-click acceleration, which is very importantspeed=oDiv.offsetLeft<target?8:-9;timeId=setInterval(function(){if(Math.abs(oDiv.offsetLeft-target)<=6){oDiv.style.left=target+'px'; //As long as the rectangle moves close to the target point, it moves directly to the target point, and the visual eye cannot detect the speed changeclearInterval(timeId); document.title=" The target "+oDiv.style.left;}else{oDiv.style.left=oDiv.offsetLeft+speed+'px';}},30);}</script></head><body><div id="div1"><span>100px</span></div><div id="div2"><span>800px</span></div><div id="div3"><span>300px</span></div><div id="div4"><span>500px</span></div><input type="button" value=" Move to the 100px place " onclick="startMove(100)"/><input type="button" value=" Move to the 300px place " onclick="startMove(300)"/><input type="button" value=" Move to the 500px place " onclick="startMove(500)"/><input type="button" value=" Move to the 800px place " onclick="startMove(800)"/><div id="grap" ></div></body></html>