Auto populate next select box based on previous field answer - php

Question

I have 2 questions if the answer to the first question is 1> I want the next answer to be auto populated as Yes. Can someone steer me in the right direction please?
<div class="field">
<!-- Number of Employees -->
<label>Number of Employees</label>
<div class="styled-select">
<select name="NoOfEmployees" class="validate[required]" data-prompt-position="topLeft:110,15">
<option value="">Please select</option>
<?php
foreach (range(0, 49) as $number) {
echo '<option value="'.$number.'">'.$number.'</option>';
}
?>
<option value="50 Plus">50+</option>
</select>
</div>
</div>
<div class="field">
<!-- Employers Liability Cover Required -->
<label>Employers Liability Cover Required</label>
<div class="styled-select">
<select name="EmployersLiabilityCover" class="validate[required]" data-prompt-position="topLeft:110,15">
<option value="">Please select</option>
<option value="Yes">Yes</option>
<option value="No">No</option>
</select>
</div>
</div>
If the answer is 0 then I just need the next question to stay as Please Select.

Answer 1

use jquery onchange , give selectbox inputs seperate id,
Use jquery val() to get selectbox value
use if condition to check its greater than 0
code shown below
<div class="field">
<!-- Number of Employees -->
<label>Number of Employees</label>
<div class="styled-select">
<select name="NoOfEmployees" class="validate[required]" id="select1" data-prompt-position="topLeft:110,15">
<option value="">Please select</option>
<?php
foreach (range(0, 49) as $number) {
echo '<option value="'.$number.'">'.$number.'</option>';
}
?>
<option value="50 Plus">50+</option>
</select>
</div>
</div>
<div class="field">
<!-- Employers Liability Cover Required -->
<label>Employers Liability Cover Required</label>
<div class="styled-select">
<select name="EmployersLiabilityCover" id="select2" class="validate[required]" data-prompt-position="topLeft:110,15">
<option value="">Please select</option>
<option value="Yes">Yes</option>
<option value="No">No</option>
</select>
</div>
</div>
<script src="https://code.jquery.com/jquery-2.1.4.js"></script>
<script>
$('#select1').on('change', function() {
if(this.value>0)
{
$("#select2").val("Yes");
}
else
{
$("#select2").val("");
}
});
</script>