JSFiddle - React, Tailwind, and code Playground

HTML

<form action="mailto:email" method="post" enctype="text/plain" name="FrontPage_Form1" target="_new" id="QuoteForm" onSubmit="return FrontPage_Form1_Validator(this)" webbot-action="--WEBBOT-SELF--" language="JavaScript">
<a name="quote"></a>

    <br>
    <table width="100%" border="0" cellspacing="0" cellpadding="0">
        <tr align="left" valign="top">
            <td><b>Date:<span class="asterick">*</span></b>

            </td>
            <td>
                <input name="dateplaced" type="text" ID="dateplaced" size="45" readonly>
                <script>
                    document.getElementById("dateplaced").value = new Date();
                </script>
            </td>
        </tr>
        <tr align="left" valign="top">
            <td><b>EC Part Number:<span class="asterick">*</span></b>

            </td>
            <td>
                <div id="container">
                    <input name="ECPartNumber1" type="text" id="1" value="#" size="10" maxlength="10">
                    <input name="+" type="button" id="+" onClick="addInput()" value="+" label="+" />
                    <input name="-" type="button" id="-" onClick="subtractInput()" value="-" label="-" />
                </div>
            </td>
        </tr>
        <tr>
            <td><b>Quantity:<span class="asterick">*</span></b>

            </td>
            <td>
                <input name="Quantity" type="text" id="Quantity" size="3" maxlength="4" value="1">
            </td>
        </tr>
        <tr>
            <td colspan="2">&nbsp;</td>
        </tr>
        <tr>
            <td width="49%"><b>Full Name:<span class="asterick">*</span></b>

            </td>
            <td>
                <input name="FullName" type="text" id="FullName">
            </td>
        </tr>
        <tr>
            <td width="49%"><b>Title<span class="asterick">*</span></b>

            </td>
            <td>
                <input type="text" name="Title" id="Title">
            </td>
       ...

JavaScript

var countBox = 1;

FrontPage_Form1_Validator = function(theForm) {

    if (theForm.dateplaced.value === "") {
        alert("Please enter a value for the \"Date\" field.");
        theForm.dateplaced.focus();
        return (false);
    }

    for (var i = 1; i <= countBox; i++) {
        var partNum = "ECPartNumber" + i.toString();
        if (theForm[partNum].value == "#") {
            alert("Please enter a value for the \"EC Part Number\" field. (slot "+i+")");
            theForm[partNum].focus();
            return (false);
        }
    }

    if (theForm.ECPartNumber1.value === "") {
        alert("Please enter a value for the \"EC Part Number\" field.");
        theForm.ECPartNumber.focus();
        return (false);
    }

    if (theForm.Quantity.value === "") {
        alert("Please enter a value for the \"Quantity\" field.");
        theForm.Quantity.focus();
        return (false);
    }

    if (theForm.FullName.value === "") {
        alert("Please enter a value for the \"Full Name\" field.");
        theForm.FullName.focus();
        return (false);
    }

    if (theForm.Title.value === "") {
        alert("Please enter a value for the \"Title\" field.");
        theForm.Title.focus();
        return (false);
    }

    if (theForm.FacilityName.value === "") {
        alert("Please enter a value for the \"Facility Name\" field.");
        theForm.FacilityName.focus();
        return (false);
    }

    if (theForm.FacilityDesc.value === "") {
        alert("Please enter a value for the \"Facility Description\" field.");
        theForm.FacilityDesc.focus();
        return (false);
    }

    if (theForm.ShippingAddress.value === "") {
        alert("Please enter a value for the \"Shipping Address\" field.");
        theForm.ShippingAddress.focus();
        return (false);
    }

    if (theForm.StateProvince.selectedIndex < 0) {
        alert("Please select one of the \"State / Province\" options.");
        theForm.StateProvince.focus();
       ...