Proportional Images: If Width Value is defined, what should height value be??

[Donn]

Hello.

I've a need for another image size. Let's say it's TINY_IMAGE.

I have my images set for proportional calculated sizing.

so if I have this code:
define("TINY_IMAGE_WIDTH", "180");
and I want the proportional part to work...

then what do I define TINY_IMAGE_HEIGHT as?

Is it:

define("TINY_IMAGE_HEIGHT", " ");

or

define("TINY_IMAGE_HEIGHT", "0");

or

something else??