warning in VB, passing variables

Hi,

i made my first VB script in GH:

Private Sub RunScript(ByVal x As List(Of OnCurve), ByVal y As List(Of OnCurve), ByRef A As Object)     

Dim arr_CurvesOut, arr_CurvesIn As New List (Of OnCurve)    

Dim i As Integer    

Dim w As Integer    

Dim arrCurvesIn(1) As OnCurve    

Dim arrCurvesOut() As OnCurve

     For i = 0 To x.Count() - 1      

arr_CurvesIn.Clear()      

arr_CurvesIn.Add(x(i))      

arr_CurvesIn.Add(y(i))      

arrCurvesIn(0) = arr_CurvesIn(0)      

arrCurvesIn(1) = arr_CurvesIn(1)      

w = OnUtil.ON_JoinCurves(arrCurvesIn, arrCurvesOut, 0.001)     arr_CurvesOut.Add(arrCurvesOut(0))    

Next    

A = arr_CurvesOut  

End Sub

Everything works good, but I have one warning, which i do not understand. As I suppose, it is related to by val and by ref variables.

"Warning: Variable 'arrCurvesOut' is passed by reference before it has been assigned a value. A null reference exception could result at runtime. (line 94)"

Could somebody explain me, what is wrong in my code?

Thx