I have the following markup:

<asp:DropDownList ID=dd1 AutoPostBack=true runat=server>

    <asp:ListItem Value=1>1</asp:ListItem>

    <asp:ListItem Value=2>2</asp:ListItem>

</asp:DropDownList>

<asp:DropDownList ID=dd2 AutoPostBack=true onchange=javascript:return true; runat=server>

    <asp:ListItem Value=1>3</asp:ListItem>

    <asp:ListItem Value=2>4</asp:ListItem>

</asp:DropDownList>

Wired up to this:

Protected Sub changed1(sender As Object, e As EventArgs) Handles dd1.SelectedIndexChanged



End Sub



Protected Sub changed2(sender As Object, e As EventArgs) Handles dd2.SelectedIndexChanged



End Sub

When dd2's index is changed, you'd expect its handler to fire, right? Well, it doesn't. Instead, it gets queued up and is fired after dd1's handler fires when its index is changed. If you take the onchange=javascript:return true; off dd2, it fires just fine.

Does anyone have any idea what's happening here?

Edit: My first answer would be that using return expressions on a dropdownlist doesn't work the same as a button's click event, but I swear I've done this with dropdownlists before.

Update: I am able to force the server event to fire by doing this in Javascript:

__doPostBack(<%=dd2.ClientID %>, '');

I don't see why I have to do this, but it works. However, I still want to do it the other way, so if someone knows, please let me know so I can mark you as answer.