The following formula is being used in spreadsheet A (Forecast) to get data
from spreadsheet B (List of Open Work Orders with various types of cost).

=IF(ISERROR(VLOOKUP($C10,WIPSUM.xls!$B$2:$AJ$2000, 21)),"0",VLOOKUP($C10,WIPSUM.xls!$B$2:$AJ$2000,21) )

Few questions regarding the above IF statement:

1)I think the the statement is saying that if the Vlookup creates an error,
then put a zero otherwise put the lookedup value in spreadsheet A. Is my
general understanding correct?

2) Spreadsheet B contains list of open work orders with the relevant costs.
If a work order is not listed in Spreadsheet B, then, as per the formula, it
should put a zero value in Spreadsheet A - at least that is my
understanding. However, I have noticed that it puts a fake value in
spreadsheet A and then I have to manually enter the right values. My concern
is that if I am not careful I may miss out on changing the values. How can
I fix this problem? Perhaps I should take out the ISERROR and let the
formula show the error sign and then I can go and manually enter the values
for the work orders closed.

3) The other alternative to point# 2 could be that I put in the next column
to the work order number an "O" for open, a "C" for closed and a blank if no
work order is listed. I tried modifying the above formula and using it put
it did not work:

If the work order is really open and listed in spreadsheet B, it will give
me an "O". Fine!
If the work order closed and not listed in the spreadsheet B, it will STILL
give me an "O".
If the no work orders is listed, say in C10, then it will give me a "C".

The modified formula is as follows:

=IF(ISERROR(VLOOKUP($C9,WIPSUM.xls!$B$2:$AJ$2000,3 5)),"C",VLOOKUP($C9,WIPSUM.xls!$B$2:$AJ$2000,35))

In Spreadsheet 'B', column B is showing work order status which is, in this
case, always an "O" for open as it does not list the closed work orders.

Thanks in advance.

SJ