MATLAB: Stateflow action language if else construct

actionaction languageif statementstateflow

My question deals with the action language used by Stateflow :
when I use something like
if (i==2)
x = 1;
I got an execution saying : Unresolved function 'if' in …
It seems that if/else constructs are not supported
Is that true ?
(I am using R2010a)