<html>
<body>
<script language="JavaScript">
function function1() {
var newOption = document.createElement("<option value="TOYOTA">");
document.all.mySelect.options.add(newOption);
newOption.innerText = "Toyota";
}
function function2() {
document.all.mySelect.options.remove(0);
}
</script>
<select id="mySelect">
<option value="HONDA">Honda</option>
<option value="ACURA">Acura</option>
<option value="LEXUS">Lexus</option>
</select>
<input type="button" value="Add" onclick="function1();">
<input type="button" value="Remove" onclick="function2();">
</body>
</html>