When you're in the design view of your SSIS package you can right click in the designer window and click the "Variables" menu item.  This should display the "Variables" tab where you can add variables to the DTS package.  I will use the example of 'vDivisionID' which I have set to be an Int32

Then you can go into the properties of the Script Task that you are working with, and you'll see "ReadOnlyVariables" and a "ReadWriteVariables" properites.  You will need to enter a comma seperated list of the SSIS variables you want to access from the script in which ever of these two properties is appropriate.  In my case I put 'vDivisionID' into the "ReadOnlyVariables" property.

Then, once you're in the script editor ready to write the vb.net code, you can access these varaibles with the Dts.VariableDispenser class like this...

    Public Sub Main()
        Dim variables As Variables
        Dim DivisionID As String

        If Dts.VariableDispenser.Contains("vDivisionID") = True Then
            DivisionID = Dts.Variables("vDivisionID").Value.ToString
            Dts.TaskResult = Dts.Results.Failure
            Exit Sub
        End If

        Dts.TaskResult = Dts.Results.Success
    End Sub

I hope this helps and makes sense, I was in a rush while writing this. Smiley