Need message box alert if formula result <10

[stephyroni]

I am working on creating a mileage log and I would like to create a pop-up alert if the mileage input is less than 10 ("Trips less than 10 miles are not reimbursable.").

I've tried a few things and they either don't work at all, or give me a message box regardless of the value in the cell. I think the problem might be that my target (column E) is a formula that links to a lookup table on another sheet: (IFERROR((VLOOKUP9(B10,Locations!$A$1:$C$100,3,FALSE)),""). Or maybe it's something else??

I have attached a copy of my worksheet. Thank you!
mileage log.xlsm

[Speshul]

If this is regarding manual entry, you can use Data Validation to do this.

See the Data Validation menu in the Data Tab, and select an Error Alert to make a popup.

[TMS]

Your VBA Project is password protected. Do you want me to break in, or will you share the password or would you prefer to upload an unprotected version of the workbook?

To save time, a Worksheet Change event will only fire if a manual change is made to the cell, or th cell is changed by code. It will not fire if the cell contains a formula, regardless of whether or not the value of the formula changes. You would either need to monitor the cell's precedents, directly or indirectly.

Regards, TMS

[stephyroni]

Oops, the password is "cinnamon".