how to bind data in autocompleted textbox

hi in my application i am using three auto completed TextBox

<asp:TextBox ID="txt_city"  runat="server"></asp:TextBox>
    <asp:AutoCompleteExtender ID="txt_city_AutoCompleteExtender" runat="server" 
    EnableCaching="true"
    CompletionSetCount="12"
    ServicePath="Autocomplete.asmx"
    ServiceMethod="Getdata"
    CompletionInterval="10"
     MinimumPrefixLength="1"
        Enabled="True"  
        TargetControlID="txt_city">
    </asp:AutoCompleteExtender> 

<asp:TextBox ID="txt_Search"  runat="server" Height="28px" Width="296px"></asp:TextBox>
    <asp:AutoCompleteExtender ID="txt_Search_AutoCompleteExtender" runat="server" 
     EnableCaching="true"
    CompletionSetCount="12"
    ServicePath="Autocomplete.asmx"
      ServiceMethod="Getusersearch"
      CompletionInterval="10"
     MinimumPrefixLength="1"
        Enabled="True" 
        TargetControlID="txt_Search">
    </asp:AutoCompleteExtender>
 
<asp:TextBox ID="txt_Palce"  runat="server"></asp:TextBox>
    <asp:AutoCompleteExtender ID="txt_Palce_AutoCompleteExtender" runat="server" 
      EnableCaching="true"
      CompletionSetCount="12"
      ServicePath="Autocomplete.asmx"
      ServiceMethod="getarearecord"
      CompletionInterval="10"
      MinimumPrefixLength="1"
        Enabled="True" 
        TargetControlID="txt_Palce">
    </asp:AutoCompleteExtender> 

here txt_City,txt_Place,txt_Search three auto completed textbox my question "when i select city in "txt_city" based on that city bind data in "txt_Search","txt_Place " " i attach my coding here please any one help me

gowthaman8870226416