[asterisk-users] Correct syntax for IF()?

[Vincent]

On Fri, 30 Nov 2007 00:30:06 -0500, Jared Smith <jsmith at digium.com>
wrote:
>Sounds like a perfect application for the ISNULL dialplan function.  Of
>course, that adds a whole new set of curly braces and parentheses to
>watch out for.

Thanks Jared for the pointer :-)

exten => s,1,Set(foo=${ISNULL(${var1})})
http://www.voip-info.org/wiki/index.php?page=Asterisk+func+isnull