SSIS Script Task To Check For File Existance

Hi all,

Let me apologize in advance for what I know is a very basic question,
but so far I'm not being terribly successful trying to find sample code
to learn from.



I'm trying to write (my first!) .Net Script in SSIS to check for the
existance of a file (since that seems to be the only way to do it).



I've created the Script Task, with the following settings:

PrecomplieScriptIntoBinaryCode = False (it complained at one point in time (possibly on validation))

EntryPoint = ScriptMain

ReadOnly Variables = ProductBuyListFileLocation, ProductBuyListFileName

ReadWrite Variable = FileFound



Now the ReadOnly variables have the 2 components necessary for a file location, i.e.:

ProductBuyListFileLocation = 'D:TestingProductInformationEnhancements'

ProductBuyListFileName = 'buyList.xls'



So, I'm now trying to check the existance with the following .Net Script code:

-------code--------

Imports System

Imports System.Data

Imports System.Math

Imports System.IO

Imports Microsoft.SqlServer.Dts.Runtime



Public Class ScriptMain



' The execution engine calls this method when the task executes.

' To access the object model, use the Dts object. Connections, variables, events,

' and logging features are available as static members of the Dts class.

' Before returning from this method, set the value of Dts.TaskResult to indicate success or failure.

'

' To open Code and Text Editor Help, press F1.

' To open Object Browser, press Ctrl+Alt+J.



Public Sub Main()

'

' Add your code here

'

Dim FileLocation As String

Dim DTSVariables As Variables



If
System.IO.File.Exists((CStr(DTSVariables("ProductBuyListFileLocation").Value)
+ (CStr(DTSVariables("ProductBuyListFileLocation").Value)))) Then

DTSVariables("FileFound").Value = 1

Else

DTSVariables("FileFound").Value = 0

End If

Dts.TaskResult = Dts.Results.Success

End Sub



End Class

-------code--------



if fails with this message, which I'm not finding too helpful:

at
ScriptTask_6c9d28f1bd3045739c4237bd588e3835.ScriptMain.Main() in
dts://Scripts/ScriptTask_6c9d28f1bd3045739c4237bd588e3835/ScriptMain:line
28



Is it complaining about not being able to find/address my ReadOnly variable? If so, what am I doing wrong?



TIA