syntax:

isNaN(number)

where:

number - a value to if it is not a number.

return:

boolean - true if number is not a number, else false.

description:

This method returns true if the parameter, number, evaluates to NaN, "Not a Number". Otherwise it returns false.

see:

global.isFinite()

example:

if (isNan(99)) Screen.writeln("Not a number");