You've already been given the answer of DV, BUT, be aware that DV is easily
bypassed, and the user could simply copy a cell with a negative number and
paste it straight over that cell which will effectively remove the DV.

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Regards
Ken....................... Microsoft MVP - Excel
Sys Spec - Win XP Pro / XL 97/00/02/03

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It's easier to beg forgiveness than ask permission :-)



"Skjetve" wrote:

How do you lock a cell, so the user can only write positive numbers in it?