Formula using calculated values from two other formulas wont work

Hi all

Has been a while since I have come unstuck and I hope my problem can be resolved...

I have used a formula in one worksheet uses two calulated values. One formula returns a value from another worksheet. The other formula is in the same worksheet in which a final value is being calculated. The final formula wont use the returned value from the second worksheet.

Am I missing something or is there some switch that needs activating or does excel not handle this sort of calculation?

Here are the formulas:

This formula (below) sits in Col AS in worksheet 1 and returns a value from Assumptions worksheet (worksheet 2).

=IF(ISERROR(INDEX(Assumptions!$E:$E,MATCH(AR10,Assumptions!$D:$D,0))),0,INDEX(Assumptions!$E:$E,MATCH(AR10,Assumptions!$D:$D,0)))

Also in worksheet 1 there are two other formulas:

One in Col AQ which is =IF(OR(H10="Y",H10="N"),AQ9+AN10,AQ9)

The result of this formula is used with the one above (in Col AS) in a second formula in worksheet 1 shown below and sits in

Col AT which is =IF(OR(H10="Y",H10="N"),AQ10+AS10,AQ9)

The formula in Col AT uses the value in Col AQ but not the value in Col AS which is the value returned from the second worksheet.

Is it something to do with values outside the active worksheet?

I look forward to your thoughts...

Many thanks in advance...

mgerada

Apologies I couldn't reply earlier. I have resolved the problem I had an error in one of the formulas. Thank you for taking the time to reply.

Regards

mgerada