(Resolved) Conversion from type 'DBNull' to type 'String' is not valid

[FastEddie]

I am importing an Excel spreadsheet, turning it into a dataset and inserting the results into SQL Server (only 100 rows).

I am having an issue with one of the date columns in Excel, which can have a value or not. The "F" column is the one that may be blank and this is the error I get: Conversion from type 'DBNull' to type 'String' is not valid.

How can I add a check to the Dim F As Date = CDate(row(5)) to handle a null?

' The use of letters instead of
    ' more descriptive variables is
    ' strictly for this sample peice
    ' of code.
    Public Sub PushDS2SQL()
        Try
            Dim row As DataRow
            For Each row In ExcelSlurp.Tables(0).Rows
                Dim A As String = CStr(row(0))
                Dim B As String = CStr(row(1))
                Dim C As String = CStr(row(2))
                Dim D As Integer = CInt(row(3))
                Dim E As Date = CDate(row(4))
                Dim F As Date = CDate(row(5))
                AddEligEmp(A, B, C, D, E, F)
            Next row
            MessageBox.Show( _
                "Eligible Employees Added", _
                "Success", _
                MessageBoxButtons.OK)
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub