JSFiddle - React, Tailwind, and code Playground
by kneidels
HTML
<script src="https://ajax.aspnetcdn.com/ajax/jquery.validate/1.13.0/jquery.validate.min.js"></script>
<form action="" class="validate">
<select id="A1" name="A1" class="required" >
<option value="">Select...</option>
<option value="1">1</option>
<option value="2">2</option>
</select>
<br> <input type="submit" name="go" value="go" />
</form>
JavaScript
$(".validate").validate();
$("#A1").on("change", function(){
var A1 = $(this).val();
if (A1=='1') {
$("#A1").nextAll('select').remove();
$('<select id="A11" name="A11" class="required" > <option value="">you selected 1, now select....</option> <option value="1">11</option> <option value="2">22</option></select>').insertAfter($(this));
$(".validate").validate();
} else if (A1=='2') {
$("#A1").nextAll('select').remove();
$('<select id="A22" name="A22" class="required" > <option value="">you selected 2, now select....</option> <option value="1">1111</option> <option value="2">2222</option></select>').insertAfter($(this));
$(".validate").validate();
} else {
$("#A1").nextAll('select').remove();
}
});