Getting Sum of DataGridView Column

I'm trying to create a TextBox outside of a DataGridView that will give the sum of values in a column within a DataGridView. I've created a query within the datatable to sum the column. If I refer to that query, it does give the sum of all the values in the column. That's fine. But I also have the ability for the user to filter the data. When I filter the data, the TextBox still gives the sum of all the values in the datatable, rather than just the values in the filtered list. Any suggestions?

Thanks,
John

[531 byte] By [reichard] at [2007-12-22]