<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <script src="http://libs.baidu.com/jquery/1.10.2/jquery.min.js"></script> <script type="text/javascript"> var countdown=60; function sendemail(){ var obj = $("#btn"); settime(obj); } function settime(obj) { //发送验证码倒计时 if (countdown == 0) { obj.attr('disabled',false); //obj.removeattr("disabled"); obj.val("免费获取验证码"); countdown = 60; return; } else { obj.attr('disabled',true); obj.val("重新发送(" + countdown + ")"); countdown--; } setTimeout(function() { settime(obj) } ,1000) } </script> <body> <input type="button" id="btn" value="免费获取验证码" onclick="sendemail()" /> </body> </html>