Validate DropDownList

[shapper]

Hello,

I have 3 DropDownLists: ddlA, ddlB and ddlC.

All these DropDownLists have a item which value is "".

I need to create a validator that fires if any of the ddls are empty.

I tried to use the CustomValidator control with a client side function
but no success.

One of the problems I see here is that I am checking 3 DropDownLists
and not just one.

But it is quite simple ... just checking if they are empty ... nothing
else.

Could someone, please, help me out?

Thanks,

Miguel