JQgrid对话框未显示在搜索运算符下拉列表中

Question

为什么对话框搜索永远不会显示运算符下拉（等于 - 不等于 - 包含 - 是，.....）！？！？

这是我的代码：

 <trirand:JQGrid runat="server" ID="JQGrid1" DataSourceID="AccessDataSource1">
        <Columns>
            <trirand:JQGridColumn DataField="OrderID" Searchable="true">
            </trirand:JQGridColumn>
            <trirand:JQGridColumn DataField="Freight" Editable="true" />
            <trirand:JQGridColumn DataField="OrderDate" Editable="true" DataFormatString="{0:d}"
                DataType="Date" Searchable="true" SearchToolBarOperation="IsEqualTo" />
            <trirand:JQGridColumn DataField="ShipCity" Editable="true" SearchToolBarOperation="Contains"
                Searchable="true" />
        </Columns>
        <ToolBarSettings ShowRefreshButton="true" ShowSearchButton="true" />
        <SearchDialogSettings ValidateInput="false" />
        <SortSettings InitialSortColumn=""></SortSettings>
    </trirand:JQGrid>