Invoice Number Generating

[LindaHoff]

Hi, I am trying to generate an invoice number on a worksheet that is in a workbook that has 3 other worksheets in it.  I have tried the following a number of videos but it will not work, I think it is because I have multiple worksheets and I am trying to generate the number on one worksheet and have it linked to the other worksheets

[#2]

@LindaHoff 

it would be helpful if you upload a sample file to understand better the problem