hi guys

i've created 2 new boolean attributes (called hiRes and loRes) for my subdiv root mesh and connected them to the Visibility attribute of my subdiv shape and poly-proxy cage (respectively).

It's working fine - now i can enter 1 or 0 in the channel box to turn them on or off.

The problem is i want to create a toggle so that when 1 is on, the other is off (hidden). I tried writing this expression but something's wrong. when i execute, it goes through without any errors, but i can't change the attribute value in the channel box (the field has turned purple).

this is what i wrote:

if (polyToSubd1.hiRes=on)
polyToSubd1.loRes=off;
else
polyToSubd1.loRes=on;

can anyone help? sorry am an expression / scripting novice and i know next to nothing about these things!

thanks
Lori