Dropdown list loses properties on post back

[ragstta]

Hi im trying to mimic the itemdata property from vb6 in asp.net.
On post back it seems to lose all attributes?

Initial Load:
? ddlCustomer.items(2).Attributes("ItemData")
"3"
On Post Back:
? ddlCustomer.items(2).Attributes("ItemData")
Nothing


Any way around this?