JSFiddle - React, Tailwind, and code Playground

HTML

<input type="image" class="previous_page_img graybutton mediumbutton" src="http://google.com/intl/en_com/images/srpr/logo3w.png" onclick="alert('hi');" alt="">

JavaScript

var onclick = $('.mediumbutton').attr('onclick');

var but =  $('<input/>', { type: "button", value: "pressme", onclick: onclick});

$('.mediumbutton').replaceWith(but);