[RESOLVED] What am i missing? (Probably really easy!)

[Kimmy4]

Hi Guys, this is the code i have:

Dim i As Integer = 0
            While sqlRdr.Read()
                Dim arrChar As Char() = sqlRdr.Item("photoType").ToString.ToCharArray()
                If Not Char.IsDigit(arrChar(1)) Then
                    For j As Integer = 0 To photoTypes.Length - 1
                        If Not photoTypes(j).ToString = sqlRdr.Item("photoType").ToString Then
                            If j = photoTypes.Length - 1 Then
                                photoTypes(i) = sqlRdr.Item("photoType").ToString
                                ReDim Preserve photoTypes(i + 1)
                                i += 1
                            End If
                        End If
                    Next
                End If
            End While

photoTypes() is just a string array declared as follows:

Dim photoTypes(0) as string

Now what i am trying to do is to add to an array only if the value doesn't already exist. Now when i run my program i get a null exception error when i get to the line:

If Not photoTypes(j).ToString = sqlRdr.Item("photoType").ToString Then

I know there is something really simple that i am missing that will fix my problem but i cant seem to figure out what it is so if anyone could help me i'd really appreciate it.
Thanks in advance for any help