selectedIndex is undefined with jQuery in dropdownlist

I have an ASP.NET dropdownlist like this: ``` <asp:DropDownList ID="ddlMyDropDown" runat="server"> <asp:ListItem>Please pick one</asp:ListItem> <asp:ListItem>option1</asp:ListItem> <asp:ListItem>option2</asp:ListItem> <asp:ListItem>option3</asp:ListItem> <asp:ListItem>option4</asp:ListItem> </asp:DropDownList> ``` A `CustomValidator` is bound to it, to see if the user chose an option. It calls the following javascript/JQuery function: ``` function checkValueSelected(sender, args) { var index = $("#ContentPlaceHolder1_ddlMyDropDown").selectedIndex; args.IsValid = index > 0; } ``` but index is `undefined` when debugging with Firebug. The JQuery selector finds `select#ContentPlaceHolder1_ddlMyDropDown`, so that's not the problem. Does the `selectedIndex` property not exist? On the internet I found examples that do almost exactly the same and it works. I'm quite lost on this one... Update This is what Firebug shows: As you can see, the `control` variable is some sort of array, with one entry which is actually what I want to be in `control`. I don't think JQuery's ID selector returns multiple values?