How does jq realize the replacement of click verification code

You can bind the onclick event handler to a picture by clicking the refresh picture verification code. Without JQ, native JS events can solve the problem. The code is as follows:

& lt input? name="txtCheckCode "？ type="text "？ class="fixedWidth "？ id="txtCheckCode "？ /& gt；

& ltimg？ src="code.jsp "？ Alt= "verification code"? height="20 "？ align="bottom "？ style = " cursor:pointer； ? Title= "If you can't see clearly, you can click on the picture to refresh"? onclick="this.src='code.jsp？ d = '+math . random()； "？ /& gt；