Writing a value to a datagrid

Hello,

I have an application that allows user to add a new record in a datagrid view for a list of users; small table.

I check to see if the user 'forgot' to add certain fields required by my program. If they forgot the field I write a default value for them. The situation is this:

1. I ADD a new record
2. The user is entered just fine while leaving out these two fields that I'm checking for.
3. This code errors out telling me that:
An unhandled exception of type 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll. Additional information: Index was out of range. Must be non-negative and less than the size of the collection.

I sure hope that you can help me!


Dim x
        x = Log_In_CredentialsDataGridView.SelectedRows(0).Cells(5).Value.ToString
        If x = "" Then Log_In_CredentialsDataGridView.SelectedRows(0).Cells(5).Value = 5

        Dim y
        y = Log_In_CredentialsDataGridView.SelectedRows(0).Cells(6).Value.ToString
        If y = "" Then Log_In_CredentialsDataGridView.SelectedRows(0).Cells(6).Value = 0