Afternoon everyone

I have 2 formulas that I need a little bit of help on. Both are working fine
but I want the cell to be blank if the result is N/A. Just not sure how I add
it in,

1st Formula
=VLOOKUP(A2,'NEW Sales booked Jan-Mar'!$1:$65536,1,FALSE)

2nd Formula
=NETWORKDAYS(H2,U2)

But I need the 2nd formula seems a little trickier

H2 will always have a date in it. But U2 wont if the VLOOKUP returns a BLANK
result
So I need the 2nd formula to read if U2 doesn't have a date in it put blank,
otherwise run the formula.

Thanks in advance for your help