JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" id="input1" /><button class='textbox' id="button1">button 1</button><br/>
<input type="text" id="input2"/><button class='test' id="button2"> button 2</button><br/>
<input type="text" id="input3"/><button id="button3" class='textbox'>button 3</button>
JavaScript
$(document).on('click', '#button2', aFunction);
function aFunction(event){
var text = $(this).prev().val();
alert("That box contains: " + text);
}