I am working on a sheet that will pull the detail text associated with a
number, after the number is typed.

I currently am using:
=IF(A4<"",VLOOKUP(A4,openwork,2,FALSE),"")
My array is approximately 8 columns by up-to 1000 rows.

I have double and triple checked that the number I am looking up is in fact
within the array, and I have made sure that both sheets have numbers
formatted as numbers (not text).

Any ideas on what to look for next?