JSFiddle - React, Tailwind, and code Playground

HTML

<select name="ddlJobRole" onchange="javascript:setTimeout('__doPostBack(\'ddlJobRole\',\'\')', 0)" id="ddlJobRole">
<option selected="selected" value="">Please Select...</option>
<option value="A">A</option>
<option value="B">B</option>
<option value="C">C</option>
</select>

JavaScript

alert( $('#ddlJobRole').attr('onchange') );