JSFiddle - React, Tailwind, and code Playground
HTML
<a id="nav_next">
<input id="submitter" type="image" name="submitter" src="/favicon.png" height="100" width="100"/>
</a>
JavaScript
$('nav_next').addEvent('click',function(){
childinput = this.getElement('input');
if ( childinput.getStyle('disabled') != 'true' ) {
alert('enabled');
}
childinput.setStyle('disabled','true').setStyle('opacity','.6');
});