JSFiddle - React, Tailwind, and code Playground

by Michel Plungjan

HTML

<input type="text" id="txtNumber">

CSS

.Error
{
color:red
}

JavaScript

$('#txtNumber').keyup(function() {
    var val = $(this).val(), error ="";
    $('#lblIntegerError').remove();
    if (isNaN(val)) error = "Value must be integer value."
    else if (parseInt(val,10) != val || val<= 0) error = "Value must be non negative number and greater than zero";
    else return true;
    $('#txtNumber').after('<label class="Error"  id="lblIntegerError"><br/>'+error+'</label>');
    return false;
});