In T2 I have this formula:

=IF((N2<(U2-80)),U2-(N2+80),0)

In U2 I have this formula:

=IF(A20,VLOOKUP(A2'SHEET1'!$A$2:$C$288,3,FALSE)*1 0,"")

Once I enter a number in A2, all formulas work fine and I get the desired
result. However, when A2 is blank, #VALUE is displayed in T2 because of
formula in U2. I need T2 to be blank until a number is entered in A2. I'm
sure it is a fairly easy fix but I can't work it out. Can someone help with
this? Thanks!