<style> *{ margin:0; padding:0; } div{ 300px; height:50px; margin:20px; } .activeColor{ background: orange; } .odd-color{ background:#ccc; } .even-color{ background: #eee; } </style> <script> window.onload=function(){ var aDiv=document.getElementsByTagName("div"), oldColor=" "; for(var i=0,len=aDiv.length;i<len;i++){ if(i%2==0){ aDiv[i].className="even-color"; }else{ aDiv[i].className="odd-color"; } aDiv[i].onmouseover=function(){ oldColor=this.className;//存储原始颜色 this.className="activeColor";//变成激活颜色 } aDiv[i].onmouseout=function(){ this.className=oldColor;//变成原始颜色 } } } </script> </head> <body> <div>1</div> <div>2</div> <div>3</div> <div>4</div> <div>5</div> <div>6</div> </body> </html>