<!doctype html> <html> <head> <meta charset="gb2312" /> <style> </style> </head> <body> <input id="test" type="text" value="默认" style="color:#999;" /> <script> function $(o){return document.getElementById(o)} $(‘test‘).onfocus = function(){ if( this.value == this.defaultValue ){ this.value = ‘‘; this.style.color = ‘#000‘; } } $(‘test‘).onblur = function(){ if( this.value == ‘‘ || this.value == this.defaultValue ){ this.value = this.defaultValue; this.style.color = ‘#999‘; } } </script> </body> </html>
原文：http://www.cnblogs.com/ghfjj/p/6306275.html