Hi Please Help me

I have a Formula that returns either 0,1 or 2 in Cell F6 deoendant on the Value of Cell C6 as shown below.

=IF(AND(C6>8.57,C6<8.59),0,IF(C6<8.56,1,IF(C6>8.59,2,)))

I need to be able to have Cell F6 empty if Cell C6 is empty but cant get it to function. Any help would be wonderfull

Thanks in advance

Cheers

Bob