<!DOCTYPE html> <html> <body> <div style="color:#00FF00"> <h3>This is a header</h3> <h3>This is a header</h3> <h3>This is a header</h3> <p>This is a paragraph.</p> </div> <script> var lis=document.getElementsByTagName("H3") for(var i=0;i<lis.length;i++){ lis[i].d=i; lis[i].onclick=function(){ for(var j=0;j<i;j++){ if(this.d==j){ lis[j].style.background="green" break; } } } } </script> <p>上面的段落被一段脚本改变了。</p> </body> </html>