Validating a select element that allows multple selections

[eluser]Eric Cope[/eluser]
I can not seem to find any mention of this anywhere. Does someone know how to validate a Select Form element that allows selecting multiple values?
Thanks.

[eluser]Nikhil Vijayan[/eluser]
Sorry editing my post : bcoz my ansr was irelvant to ur question .. i misundertood the question..

and also do u have noticed that if we give form elemnts name as array

like <input type="checkbox" name="delete[]" value="1">
<input type="checkbox" name="delete[]" value="2">
<input type="checkbox" name="delete[]" value="3">

we cant validate it using ci validation class