<html><head><script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js"></script><script>$(document).ready(function(){ $(":submit").css("background-color","red");});</script></head><body><form action="">Name: <input type="text" name="user"><br>Password: <input type="password" name="password"><br><button type="button">Useless Button</button><input type="button" value="Another useless button"><br><input type="reset" value="Reset"><input type="submit" value="Submit"><br></form></body></html>