<!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=utf-8" /> <title>无标题文档</title> </head> <script type="text/javascript"> var defaultValue = '请阐述您的理由'; </script> <body> <textarea onfocus="if(this.value==defaultValue)this.value=''" onblur="if(this.value=='')this.value=defaultValue" id="">请阐述您的理由</textarea> </body> </html>