Crytal reports with static paramter, need to select multiple values

Hi Guys,

I have a report where i have 4 static parameters (Country, State, from_date,to_date).

So i have a requirement where, user need to select multiple states. When i change the multiple values to be true it opens up a formula and say This array must be subscripted and the formula contains cstr(state,0). Backend i have query written where state in {?state}. Can anyone provide solution for the above.

Thanks,

Naresh.