Problems using unions in DAVE

Hi there,

I am trying to use unions in Dave but run in syntax problems. Here is the sample code

typedef union
{uint16_t a;
uint32_t b;
} Mem;
int main(void)
{
Mem->a=5; <--- ../Main.c:96:4: error: expected identifier or '(' before '->' token
}

the declaration seems to be ok, however I can not access the variable. Does anybody know, what I need to do?

thanks in advance,
Felix