Testing value in range
var nValue = 0;
if (nValue >= 0 && nValue <= 100) {
alert("value between 0 and 100, inclusive");
} else if (nValue > 0 && nValue < 100) {
alert("value between 0 and 100 exclusive");
} else if (nValue > 100) {
alert ("value over 100");
} else if (nValue > 0) {
alert ("value is negative");
}