asp.net help

[duel pasta]

Okay, so

I have 2 dropdownlists on my page. both dropdownlists are bound to data in a database. Now I have a datasource, but I want it so that if you select a subject in the first dropdownlist, another dropdownlist gets visible with the different dates of the courses.

cboOndedrwerpen are subjects.

now the only problem is, when I select a subject, the other subjects dissapear from the dropdownlist, because the datasource gets filtered and it will stay filtered, how can I make it so that everytime I pick a subject the dropdownlist gets filled with all subjects again?

Do you think I should use a datareader?

ProtectedSub cboOnderwerpen_databound(ByVal sender AsObject, ByVal e As System.EventArgs) Handles cboOnderwerpen.SelectedIndexChanged
Me.dtsOnderwerpen.FilterExpression = "onderwerp= '" & Me.cboOnderwerpen.SelectedValue.ToString & "'"
dteGegevens.Visible = True
EndSub


EndSub
ProtectedSub cboDatum_SelectedIndexChanged(ByVal sender AsObject, ByVal e As System.EventArgs) Handles cboDatum.SelectedIndexChanged
Me.dtsOnderwerpen.FilterExpression = "datum= '" & Me.cboDatum.SelectedValue.ToString & "'"
EndSub

[D1st0rt]

Are you submitting the form after selecting the first value?

[duel pasta]

Well, I just want to show the future courses in a dropdownlist and sometimes one course has more dates so I want them to first select a course then a date but the filtering is a pain in the ass. If they have selected the subject and the date they have to fill in their name and their department then they click a button to sign up for it. I've tried to load the page again when they select a subject but then my datesource will not be filtered anymore so it doesnt show the information of the selected course in the formview :P

Hope that makes sense