JSFiddle - React, Tailwind, and code Playground
HTML
<form name="Web Order Form" id="Web Order Form">
<table style="position:absolute; left:580px; top:210px; height:34px;" border="0" bordercolor="#FFFFFF" style="background-color:#FFFFFF" width="50%" cellpadding="5" cellspacing="5">
<tr style="position:absolute; left:0px; top:-42px;">
<td>Select Report:</td>
<label style="font-size:16px" for="comparator">Comparator:</label>
<td>
<select id="comparator" name="comparator" onChange="return changeTextBox();">
<option value="please_select" id="please_select">Please Select...</option>
<option value="billing_report" id="billing_report">Billing Report</option>
<option value="courier_report" id="courier_report">Courier Report</option>
<option value="management_summary_report" id="management_summary_report">Management Summary Report</option>
<option value="production_report" id="production_report">Production Report</option>
<option value="prospect_list" id="prospect_list">Prospect List</option>
<option value="staff_absence_report" id="staff_absence_report">Staff Absence Report</option>
<option value="stock_report" id="stock_report">Stock Report</option>
</select>
<label style="font-size:16px" for="to">Value:</label>
<input type="number" id="value" disabled/>
</td>
</tr>
<tr>
<div style="position:absolute; left:545px; top:130px; width:510px; height:420px; border:1px solid black">
<tr>
<td>From:</td>
<td>
<input type="input" value="from" id="from">
</td>
<td>To:</td>
<td>
<input type="input" value="to" id="to">
</td>
</tr>
...
JavaScript
function changeTextBox()
{
var comp = document.getElementById('comparator');
resetFields();
if (comp.value == 'billing_report') {
document.getElementById('from').disabled = false;
document.getElementById('to').disabled = false;
document.getElementById('company').disabled = false;
document.getElementById('salesperson').disabled = false;
} else if (comp.value == 'courier_report') {
// Enable the fields you want
}
}
function resetFields() {
document.getElementById('from').disabled = true;
document.getElementById('to').disabled = true;
document.getElementById('component').disabled = true;
document.getElementById('company').disabled = true;
document.getElementById('job_no').disabled = true;
document.getElementById('salesperson').disabled = true;
document.getElementById('staff_name').disabled = true;
}