AJax Dop down items listed in next panel

Hi,

Iam using AJax drop down ,when i click the drop down button the drop down items are listed in next panel.please help me.I have attched the image .

My code is

<td width="145"  >
    <Ajx:ComboBox ItemInsertLocation="Prepend"  CssClass=""
 
            ID="ddlaccount"  ToolTip="Enter Customer name" DropDownStyle="DropDownList"  
            AutoCompleteMode=Append     runat="server"  AutoPostBack="true"
         TabIndex="3" Height="19px"></Ajx:ComboBox></td>