<!DOCTYPE html>
<html>
<body>
<h3>A demonstration of how to access a SELECT element</h3>
<select id="mySelect" size="4">
<option>Apple</option>
<option>Pear</option>
<option>Banana</option>
<option>Orange</option>
</select>
<p>Click the button to get the number of option elements found in a drop-down list.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var x = document.getElementById("mySelect").length;
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>