In two words: you don't.

In many more words: You can't restrict a variable from having any value it gets assigned. You can, however, write a validation block to check for valid values and complain|die|ignore the rest. I believe that's how it's being done in most cases...

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An idea is not responsible for the people who believe in it...

In reply to Re: How do I restrict a variable to a range of values? by bofh_of_oz
in thread How do I restrict a variable to a range of values? by tphyahoo

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