simple question

this must be some basic mistake i am doin but i am new to VB..

i have a combo box 'name'  on my form.
i also have a options 'checkbox' control array.

a(0)
a(1)
a(2)


i am seeting name.locked =true when the form loads.

when user a(0) options box is clicked i want the combobox to be unlocked
so i wrote


Private Sub a_Click(Index As Integer)
If a(0).Value = True Then name.Locked = False
End Sub

but this is givinfg me a syntax error

use of invalid quantifier for the use of name in name.locked


what am i doing wrong here?

how to disable A COMBO BOX and enable it programmatically?

thanks