Descobri como fazer isso !!!
<SCRIPT>
function between(x, min, max) {
return x >= min && x <= max;
}
function message() {
var s = document.getElementById('item1');
if (s.value == 0) {
alert("Please select an option!")
}
else if (between(s.value, 1, 10)) {
alert("Type1")
}
else if (between(s.value, 11, 20)) {
alert("Type2")
}
else if (between(s.value, 21, 25)) {
alert("Type3")
}
}
</SCRIPT>