My problem: I have two ranges R16 and R01. These ranges were set up by swiping each range and then renaming them in the upper left panel of the sheet. Each range requires users to fill in each cell with a value. R16 requires users to enter a number of 0 through 5. The range R01 requires a value of 0 or 1 to be entered. NO cell can be left blank in any cell within these two ranges. These ranges and requirements are specific to this sheet only. It would be nice if at the time of user entering a number, an error message appeared like [invalid entry] if the value inputted was outside parameters set. For example, in R16, if someone entered 12 or -1 they would be alerted. Finally when the user presses a button on the page to use these values in a separate process, it is essential to check that no cell is left blank. I am trying to find a way to halt the running of the marco (via the button) if these parameters above are not met. Thank you