DropDownList with ScrollBar for long list of Items in ASP.Net

You will again have to set position:absolute and then align your DropDownList by setting left and top to get desired position on page

  <style type="text/css">
        #DDLcity1
        {
            width: 128px;
            margin: 0 15px 0 0;
            font: 12px tahoma;
            direction: rtl;
            max-height: 200px;
            overflow-y: scroll;
            position: absolute;   
            left:10px;
            top:5px;
            z-index:1;        
        }
    </style>
    <asp:DropDownList ID="DDLcity1" runat="server" CssClass="DDlcityE" ForeColor="#ca0202"
            onmousedown="this.size=5;" onfocusout="this.size=1;" ondblclick="this.size=1;"
            AppendDataBoundItems="True" AutoPostBack="true">
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
            <asp:ListItem Text="Test"></asp:ListItem>
        </asp:DropDownList>
        <br />
    <asp:Label Text="text" runat="server" />