QueryExtender with dropdown list

i am using QueryExtender with dropdownlist to filter gridview ( datasource : EntityDataSource).

  <asp:SearchExpression SearchType="StartsWith" DataFields="Status" >
    <asp:ControlParameter ControlID="ddlStatus" Type="String"   />
  </asp:SearchExpression>

Where i bind my ddlStatus from database with default value : "Select" But when i run project it takes by default value "Select" for Field "status" and gives empty grid. But on Pageload i want to show all the records after user can select different status from dropdownlist and based on that filter should work.

how can we show all the data with dropdownlist value selected as default "select"

Just Found solution here in book: Entity Framework 4.0 Recipes: A Problem-Solution Approach

Used PropertyExpression instead of SearchExpression

<asp:PropertyExpression>
    <asp:ControlParameter ControlID="ddlStatus" Type="String"   />
</asp:PropertyExpression>

and leave value blank according to Bala R comment

<asp:ListItem Text="Select" Value="" />

Try using DefaultValue like this

<asp:ListItem Text="Select" Value="Select" />

and

<asp:SearchExpression SearchType="StartsWith" DataFields="Status" >
    <asp:ControlParameter ControlID="ddlStatus" Type="String" Default="Select"  />
 </asp:SearchExpression>