My form calculates a payment after adding all of the fields that affect the
total financed amount. Two of the fields that are added to the total financed
amount calculates the credit life and disability premium respectively. If the
credit life and/or the disability Insurance is not selected they return a
blank field.
As long as both Life and disability are both selected the payment
calculates fine. But if either one is not selected and therefore "blank"
then
the payment = "blank".
See the formula below.
How can I correct this problem? Thanks.

=IF(ISERROR(PMT(AX7/12,BA6,AX4+CE22*CB8+CD14+CC19+CE22+CE26+CE29,,0)), "",-PMT(AX7/12,BA6,AX4+CE22*CB8+CD14+CC19+CE22+CE26+CE29,,0))

CE26 and CE29 contain the formulas that are causing the problem.
Thanks.