If you're using a database to get the items for the list, you can use distinct as well. E.g.

SELECT DISTINCT Id, Description FROM SomeTable

HtH,

Imar
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Imar Spaanjaars
Everyone is unique, except for me.

i write the code as you said:select distinct HGNo from dbo.HGinf
but the page just shows the packground and nothing else and when i write it like this:
select * from dbo.HGinf it shows the page crrectly.

SELECT * retrieves all columns and all records from the database.

select distinct HGNo selects all unique values for the column HGNo

However, with the latter statement, you're not selecting other columns than HGNo. I take it your code does require these columns.
Do you get an error? Do you see a (hidden) error when you look at the source of the page in the browser?

Imar
---------------------------------------
Imar Spaanjaars
Everyone is unique, except for me.

i don't get any hidden or non hidden error.just it doesn't show me anything.just my packground and nothing else

hello again.i still have problem with my page.i don't want to have repeated value in database in my child select menu and when i use distinct for my child select menu it doesn't show me anything just page background and nothing else.even it doesn't show images.what should i do.help me please
thank you