<!DOCTYPE html>
<html>
<body>
<p>Select a display type in the list below to change <span id="mySpan" style="color:blue;">this span element's</span> display type.</p>
<select onchange="myFunction(this);" size="3">
<option>block
<option>inline
<option>none
</select>
<script>
function myFunction(x) {
var whichSelected = x.selectedIndex;
var sel = x.options[whichSelected].text;
var elem = document.getElementById("mySpan");
elem.style.display = sel;
}
</script>
</body>
</html>