Mecanim parameter not showing up in Inspector?

Hi

In a mecanim demo scene I want to add a parameter that is an Integer.

In the Animator window, I can add a parameter of type Integer but it doesn't appear in the drop-down list in the Inspector - the only two choices are Speed and Direction (set as float).

I'd added a section to the code to (I thought) handles this :

void Update () { if(avatar) { int test = 1; avatar.SetInteger("Myint", test); // more code here

Am i missing something obvious? Thanks D