JSFiddle - React, Tailwind, and code Playground
HTML
<input id="mail1" class="nohighlight" type="text" MaxLength="35" />
<input id="button" type="button" value="click" onclick="validate(this);" />
CSS
.highlighted{
border-color: red;
}
.nohighlight{
border-color : "";
}
JavaScript
function validate(obj){
alert("hai");
var str = obj.value;
var exp=/^[a-zA-Z0-9+\.]+@(([a-zA-Z]+\.)+[a-zA-Z]{2,3})$/;
if (!exp.test(str)) {
alert("invalid");
$("#mail1").switchClass("nohighlight", "highlighted", 1000);
}
}