change on number html onchange code example
Example 1: onchange on select tag
<select id="comboA" onchange="getComboA(this)">
<option value="">Select combo</option>
<option value="Value1">Text1</option>
<option value="Value2">Text2</option>
<option value="Value3">Text3</option>
</select>
Example 2: js select on change value
document.getElementById('my-select').addEventListener('change', function() {
console.log('You selected: ', this.value);
});