After following, you can keep track of his dynamic information in a timely manner
Courses in the relevant section：html basics
单标签，双标签，block，inline，inline-block，img和input属于inline-block
2019-01-130个赞
Courses in the relevant section：Form events (1)
onchange()：是值改变，并且焦点离开了文本框时触发
2019-02-020个赞
Courses in the relevant section：Principles of movement
offsetWidth的值是数值
2019-02-070个赞
