Change JavaScript NaN message to someone else

Question

I have an input[type="text"] that throws a NaN error until another field is populated. I know why the message appears, this is not a problem, it is correct. I'm just wondering if I can change "NaN" to something more descriptive for the user.

Answer 1

 if(isNaN(input.value)) { input2.value = '';//or a message of your choice } 

Answer 2

Check the value with isNaN (value), and if true, then process it however you want.