Format Cells custom set up

[Newbienew]

I am looking to use format cells options to have a prompt that shows up in the cell to give direction such as "Enter Work Code Here" or " Work code Here" when there is nothing in the cell. Once its been entered, the messages is not long displayed unless the number and letters are entered.
Below i got from a site but should give a prospective of what I am aiming for

For example, the custom format for a Federal Tax ID looks like,
“TIN “###-##-####;”Enter nine positive digits”;”Enter your tax ID”
If the user enters a positive nine digits, then it appears as
TIN 123-45-6790
If the user enters a negative number, the message “Enter nine positive digits” appears. If a zero is entered as the default, then the prompt “Enter your tax ID” appears.

 

[bobsan42]

I suggest you use a combination of Custom number format and Data validation:
Select the cell to apply them to. Press Ctrl+1 (Cell formatting). Go to Number tab and select Custom in the list.
in the text field under Type paste this:

"TIN "000-00-0000;[Red] "invalid TIN";[Red] "invalid TIN"

Press ok.
Go to Data-> Data Validation.
On the settings tab select to allow Whole Number, check ignore blank, Data: between, Minimum: 100000000, Maximum: 999999999
On the Input message tab: check Show input message when ... , title: Enter Tax ID, input message: Enter nine positive digits (that's strange digit can't be negative - they are digits, not numbers)
On the Error alert tab: check Show error alert after ..., style: whatever you like, Title: Incorrect Tax ID, Error message: Enter nine positive digits
Press ok. then Save
That's it I think.
Let us know if it works for you.

 

[bobsan42]

Only one tiny detail - if TINs can start with zero(s) then my suggestion is not the 100% right solution.