dropdown list in a datagrid

i have one dropdownlist inside a datagrid having values 1,2,3,4,5. according to this quantity i need to perform some calculations which will be displayed in anext cell of the datagrid. but it is not working.

protected void dlistShopCart_ItemDataBound(object sender, DataGridItemEventArgs e)
{
if(e.Item.ItemType==ListItemType.AlternatingItem | e.Item.ItemType==ListItemType.Item)
{
int[] options = {1,2,3,4,5};
DropDownList list1 = new DropDownList();
list1 = (DropDownList)e.Item.FindControl("ddlQty");
list1.DataSource = options;
list1.DataBind();
//e.Item.Cells[4].Text=list1.SelectedItem.Text;
}

}



public void ddlQty_change(object sender,System.EventArgs e)
{
DropDownList list = (DropDownList)sender;
TableCell cell = list.Parent as TableCell;
DataGridItem item=cell.Parent as DataGridItem;
int index=item.ItemIndex;
item.Cells[2].Text=list.SelectedItem.Text;
}