if (GridView1.Rows.Count > 0)
{
for(K=1;k>GridView1.Columns.Count-1;k++)
{
decimal amount = 0;
foreach (GridViewRow row in GridView1.Rows)
{
amount += Decimal.Parse(row.Cells[K].Text, System.Globalization.NumberStyles.Any);
}
GridView1.FooterRow.Cells[0].Text="amount";
GridView1.FooterRow.Cells[K].Text = string.Format("{0:F0}", amount);
}
}