Vlookup based on 2 vlookup values

Here is the formula I use:

=IF(ISERROR(VLOOKUP(H5;SHEET2!B:AB;3;FALSE));"";VLOOKUP(H5;SHEET2!B:AB;3;FALSE))

I would need to use that same formula based on 2 lookup value:

IF cell F5 is empty "" Then use that formula:

=IF(ISERROR(VLOOKUP(H5;SHEET2!B:AB;3;FALSE));"";VLOOKUP(H5;SHEET2!B:AB;3;FALSE))

BUT IF cell F5 is NOT empty or IF H5 is empty then use that formula:

=IF(ISERROR(VLOOKUP(F5;SHEET2!B:AB;3;FALSE));"";VLOOKUP(F5;SHEET2!B:AB;3;FALSE))

How could I combine these two formula?

Many thanks in advance,
Graig

=if(iserror(vlookup(if(f5="";h5;f5);sheet2!b:ab;3;false));"";vlookup(if(f5="";h5;f5);sheet2!b:ab;3;false))

Hello the two first reply work but I only get a result when I fill the cell F5.

If I empty the cell F5 and fill the Cell H5 I do not get the result I should get...If I have my formula in one cell and one of the two first you gave me I get the correct result but in two different cell the idea was to gather the formulas and be able to use two lookup value (not at the same time..)

Thanks,
Graig

Hi Graig,

How are you "emptying" F5? I've known some people to press Space, instead of Delete, so that they see an "empty" cell. However, that cell would contain " ", not "". Which would explain why those formulae don't work as expected. If that isn't the case, perhaps we need a little more explanation of your data and expected results.