<!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> <title> new document </title> <meta name="generator" content="editplus" /> <meta name="author" content="" /> <meta name="keywords" content="" /> <meta name="description" content="" /> </head> <body> <button onclick='godDay()'>点我</button> <div id='demo'></div> <script> //根据系统时间自动问好 document.write('点按钮会向你问好哦') function godDay(){ var x=''; var time=new Date().getHours(); if (8<time<13) { x='上午好'; } else if(13<time<17) { x='下午好' ; } else { x='晚上好'; } document.getElementById('demo').innerHTML=x; } </script> </body> </html>