I worked over 1 hour on a 1-pixel-thing, here is the code:
                <div id="Zeitraum" style="border: 1px solid black; width: 200px; padding:5px;">
                Zeitraum:
                <asp:DropDownList  ID="ddlZeit" runat="server" >
                    <asp:ListItem Text="10 Tage" Value="10"></asp:ListItem>
                    <asp:ListItem Text="30 Tage" Value="30"></asp:ListItem>
                    <asp:ListItem Text="60 Tage" Value="60"></asp:ListItem>
                    <asp:ListItem Selected="true" Text="Alle" Value="100"></asp:ListItem>
                </asp:DropDownList>
                 
                <asp:ImageButton ID="imgSend" runat="server" ImageUrl="~/Images/Icons/NavForward.png" Width="15px" Height="15px" style="" />
            </div>
Here is the image: http://s2.imgimg.de/uploads/Capture04273f43PNG.png
The ImageButton is not in the middle like the text and the DropDownList. Why?
I tried margin and padding and many many other things, but nothing helped.