Excel: IF and AND statement for dates, blanks and values

I've got a spreadsheet which lists the hire start date for our fleet of vehicles, it lists the milage and each car needs a service every 12,000 miles.

I'm trying to use Conditional Formatting to highlight cars which need a service.

First one (less than 12000 miles works fine)

Next one should say this:

If N1 (cell of 2nd service) is blank and mileage (I1) is between 12,000 and 24,000 miles, highlight yellow.

Here it is:

=IF(AND(ISBLANK(N1),(I1>24000,I1<12000))

As it's in the Conditional Formatting tool it is just giving me a generic error.

Any ideas?

Thanks