High lighting cells in different worksheets within the same workbook also from a different

Hi All.
A workbook with multiple worksheets. see attachment.
(Assuming this is a equipment rental co.)
The master, logs all the equipments.
Sheets 2, 3 and etc are for the sales dept.

The following is what I'm hoping to achive.
When an entry or entries were made on sheet 2 or 3, the cells on the master will automatic highlighted. (meaning that the piece of equipment has been booked for)
eg: when 100 is entered on sheet2 or sheet3, cell A1 on the master will highlight itself with color.

Thanking you all for the help.

Cookster

Hello Dili.
I'll try it out and get back to you soon.

Thanks.

Cookster.

Hello Dili.
Conditional Formatting won't allow me to apply the fomula.
Please assist.

Thank You.

Cookster

Thank Fortis .
It works great in your example. That is what I have been looking for.
How do I get it to work from my end?
I know what name range is. I don't know what CF meant.
I would rreally appreciate If you could give me the step by step instruction on how to apply the fomulas.
I have very little knowledge on Excel. I am a machine mechanic by trade.
Again, any assistance will be greatly appreciated.

Cookster

Hi All
Thanks very for the help.
I got it work.

cookster

Thanks Fotis.
I got it to work now.

Hi Dili.
Thanks for the help.
Cookster