Insert the values in GridView1_RowCancelingEdit

protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
fillgridview();
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
fillgridview();
}