Creating Object Using Array In A Loop

I would like to populate an array with an object. In other words, I would like for each element in the array to consist of an object that has several elements. Below is some code so you can see what I'm talking about:

Function buildObj()
   Dim countLimit As Integer = 5
   Dim mArray() As myObject

     While reader.Read()
          For counter = 0 To countLimit - 1
                mArray(counter).objVal1 = reader.GetValue(0)  'Error is here
                mArray(counter).objVal2 = reader.GetValue(1)
                mArray(counter).objVal3 = reader.GetValue(2)
                counter += 1
          Next
     End While

     Return mArray

End Function

Dim showValArr As Array = buildObj()
Response.Write(showValArr(0).objVal1.ToString)

When I build my site, I get the following error:
Object reference not set to an instance of an object.

It's pointing to the line that says "Error is here". Any ideas would be very helpful.
Thank you!