I would like to know how to have a cell change color when an error occurs...I
know its possible 'cause I have two other cells that turn red when an error
occurs in my entries but I can't figure out for the last one. For example,
cells contain either a COUNTIF or IF formula. When the user enters to many
entries other than what is allowed, the cell will turn red so that you know
an error has occured.

An example of where we are using this: employees are allowed 15 vacation
days, if they are enter 16 days in the planner by mistake, the cell where the
formula is will turn red.

Any ideas what I'm looking for here?

Thank you,
CC