Restricting the sign of an entry

[SMARIE]

I am trying to restrict the sign of the number a user can enter based on the sign of a different cell. For example, in the below, I want to restrict the user so that they can only enter a positive number in B1 since A1 is positive. In the same manner, they should only be able to enter a negative number in B2 since A2 is negative. Anyone have ideas?

 

[DRSteele]

Use data validation. Set it up to restrict the user so he can only enter a number between 0 and the maximum number with that sign available in Excel. That number here I've used as 9.99 x 10^307

Like this:

 

[SMARIE]

That worked! Thank you

 

[Rick Rothstein]

Using DRSteele's layout, you could also use this Custom Data Validation formula as well...

=OR(D4=0,SIGN(C4)=SIGN(D4))

 

[DRSteele]

You're welcome, Marie. I'm glad to have helped.