Macro to generate a unique number on a shared workbook.

Hi,

I am totally new to macro but I believe that my problem can be solved using a simple macro.

My requirement is as below:

I have a shared workbook (which is used by approx 25 people). This workbook should have a macro assigned to a button which when clicked should generate a unique number starting from 1000. I believe the challange here is the shared workbook. As this workbook will be open with all the people there shouldn't be any duplicate numbers in case if two or more people press the button at the same time.

FYI- I do not need a random number every time the button is clicked, just the next number in series will suffice.

I would appreciate if the macro also has an explanation along with as this would help me better understand it and learn a few things too.

Thanks in advance.

I removed the .Close True as it was closing the workbook once the macro runs. I have assigned the macro to a button and it works verry nicely. Thank you verry much for the explanations it really helped me understand the code. 1 more request can we tell the macro to save the workbook once the button is clicked?

I have edited the code above for you.

Thanx for the quick response... Do I need to save the shared workbook as a macro enabled workbook (.xlsm) or should it be saved as normal (.xlsx)?
Please guide me if I am doing something wrong...

Hi the workbook that the user modifies needs to be macro enabled.

The Master file where the number is stored does not need to be macro enabled.