JSFiddle - React, Tailwind, and code Playground
HTML
<form name="a">Text "A" : <input name="a" /></form>
<br />
<form name="b">Text "B" : <input name="a" /></form>
<hr>
<button>check</button>
JavaScript
var doc=document;
doc.body.onclick=function(e){
var el;
(el=/*@cc_on!@*/0?event.srcElement:e.target)
.tagName=="BUTTON" &&
alert(doc.a.a.value==doc.b.a.value?"идентичны":"не сходятся");
}