JSFiddle - React, Tailwind, and code Playground

HTML

<div class="row">
    <div class="col-sm-12">
        <div class="form-group" id="FromClass">
            <label class="col-sm-offset-3 col-sm-2 control-label">From</label>
            <div class="col-sm-6 col-md-4" id="FromDiv">
                <select name="RegCashMove_From_DropDownList" class="form-control" id="RegCashMove_From_DropDownList">
                    <option value="- - Please select - -">- - Please select - -</option>
                    <option value="AJBIC">AJBIC</option>
                    <option value="FSS">FSS</option>
                </select>
            </div>
        </div>
        <div class="form-group" id="ToClass">
            <label class="col-sm-offset-3 col-sm-2 control-label">To</label>
            <div class="col-sm-6 col-md-4" id="ToDiv">
                <select name="RegCashMove_To_DropDownList" class="form-control" id="RegCashMove_To_DropDownList">
                    <option value="- - Please select - -">- - Please select - -</option>
                    <option value="AJBIC">AJBIC</option>
                    <option value="FSS">FSS</option>
                </select>
            </div>
        </div>
        <div class="form-group" id="AmountClass">
            <label class="col-sm-offset-3 col-sm-2 control-label">Amount</label>
            <div class="col-sm-6 col-md-4" id="AmountDiv">
                <div class="input-group">
                    <div class="input-group-addon">£</div>
                    <input name="RegCashMove_Amount_TextBox" class="form-control" id="RegCashMove_Amount_TextBox" onblur="FormatCurrency(this);" type="number" step="any" value="" placeholder="0.00">
                </div>
            </div>
        </div>
        <div class="form-group" id="FrequencyClass">
            <label class="col-sm-offset-3 col-sm-2 control-label">Frequency</label>
            <div class="col-sm-6 col-sm-4" id="FrequencyDiv">
                <select name="RegCashMove_Frequency_DropDownList" class="form-control"...

JavaScript

$(document).ready(function () {        $('#RegularCashMovements_Submit_Button').attr('disabled', 'disabled');

            function updateFormEnabled()
            {
                if (verifyAdSettings())
                {
                    $('#RegularCashMovements_Submit_Button').attr('disabled', '');
                }
                else
                {
                    $('#RegularCashMovements_Submit_Button').attr('disabled', 'disabled');
                }
            }

            function verifyAdSettings()
            {
                if ($('#RegCashMove_From_DropDownList').val() != '- - Please select - -' && $('#RegCashMove_To_DropDownList').val() != '- - Please select - -' && $('#RegCashMove_Amount_TextBox').val() != '' && $('#RegCashMove_Frequency_DropDownList').val() != '0')
                {
                    return true;
                }
                else
                {
                    return false
                }
            }

            $('#RegCashMove_From_DropDownList').change(updateFormEnabled);
            $('#RegCashMove_To_DropDownList').change(updateFormEnabled);
            $('#RegCashMove_Amount_TextBox').change(updateFormEnabled);
            $('#RegCashMove_Frequency_DropDownList').change(updateFormEnabled);
});