how to cast ice block and not cancel it?

yes I read the macro sticky, nothing there.

I, as I am sure many people have, might end up pressing ice block an extra time. This ends up cancling it, and has gotten me killed more than a few times. is there a macro or option such that I can afford an accidental extra press of the button and not die horribly because iceblock instantly falls off me?
I thought you actually had to use a macro to make it possible to cancel it by hitting the same button.
#showtooltip Ice block
/Cast !Ice block
blech humans

#showtooltip Ice block
/Cast !Ice block

Make a seperate macro with /cancelaura Ice Block attached to it.

For example, I have...

#showtooltip Ice Lance
/cancelaura Ice Block
/cast Ice Lance

Make sure it's an easy access key so you can get out of the block quick if need be (just be sure it's the right choice if you do)!