JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://extjs-public.googlecode.com/svn/extjs-3.x/release/resources/css/ext-all.css">
<script src="http://extjs-public.googlecode.com/svn/extjs-3.x/release/adapter/ext/ext-base.js"></script>
<script src="http://extjs-public.googlecode.com/svn/extjs-3.x/release/ext-all.js"></script>
<script src="http://w3forge.org/js/MoneyExchange.min.js"></script>
<div id="exampleExchange"></div>

CSS

body {
    padding: 10px;
    font-family: "Trebuchet MS", Tahoma, Verdana, Sans;
    font-size: 9pt;
}
.example {
  padding: 10px;
  color: grey;
  text-align: center;
  border: 1px inset #e0e0e0;
  margin: 2px;
}
.example b {
  font-size: 1.5em;
  color: black;
  margin: 5px;
}

JavaScript

Ext.onReady(function() {

  //
  Ext.apply(Ext.money.Exchange.defaults,{
    rates: [ // override global default rates for demo, these are USD->* exchange rates.
      ['inr','Rupees','1,000.00 INR',1],
      ['usd','Dollars','1,000.00 USD',1],
      ['eur','Euro','1,000.00 EUR',0.73136839],
      ['chf','Francs','1,000.00 CHF',0.945275],
      ['gbp','Pounds','1,000.00 GBP',0.615527],
      ['rub','Rubles','1,000.00 RUB',29.1650],
      ['crc','Colones','1,000.00 CRC',496]
    ]
  });

  var
  // create monex instance
  monex = new Ext.money.Exchange({
    source: 'gbp',
    target: 'usd'
  }),

  // create inline extension for combobox selectors.. saves code
  mxCB = Ext.extend(Ext.form.ComboBox,{
    width: 100,
    store: monex.getStore(),
    editable: false,
    valueField: 'id',
    displayField: 'name',
    triggerAction: 'all',
    forceSelection: true,
    mode: 'local',
    listeners: { select: function(p){ updateExample(); } }
  }),

  updateExample = function(source,target){
    source = source || Ext.getCmp('cS').getValue();
    target = target || Ext.getCmp('cT').getValue();

    // update monex with new settings
    monex.setSource( source );
    monex.setTarget( target );

    // update displayed result
    var amount = parseFloat(Ext.get('cA').getValue());
    Ext.get('tResult').update( String.format('<b>{0}</b> is equal to <b>{1}</b>',
        monex.formatCurrency(amount, monex.getCurrencySource()),
        monex.convert(amount)) );
  };

  // create main calculator panel
  new Ext.Panel({
    title: 'Example Exchange Rate Calculator',
    renderTo: 'exampleExchange',
    width: 400,
    items: [
      {xtype:'panel',id:'tResult',cls:'example'},
      {xtype: 'form',padding:10,border:false,labelWidth:50,labelAlign:'right',items:[

        // amount to convert
        { xtype: 'textfield', id:'cA',value: 10000,fieldLabel:'Amount',
          listeners: { change: function(p){ updateExample(); } } },

        // default value to source currency
   ...