问个【EXT】关联 store 的传参问题，分页传参....

大家好，请大家帮我看看这个问题，应该很简单，只是我不会

我在GridPanel里面用了HT.PagingBar,它关联了store，store里面有url连action,这样就实现了分页

但我现在的问题是，在点分页的时候要把另一个Panel的fields的值传过去，我就卡着了，不知道怎么传

我想点击分页的时候把plan.car.selectType 的值传过去

JScript code

PlanCarView = Ext.extend(Ext.Panel, {
    initUIComponents: function() {
        fields[{
--------------------   想传这个  -------------------------------------
            id:"plan.car.selectType",
                hiddenName: "selectType",
                xtype: "combo",
                mode: "local",
                width: 80,
                editable: false,
                triggerAction: "all",
                store: [["planId", "活动编号"], ["accid", "客户编号"],["gstName","客人姓名"],
                ["cname","营业部门"],["iname","车辆型号"],["rmno","房号"],["place","出车线路"],
                ["begDate","出车时间"],["endDate","返车时间"],["remarks","备注"],["clerk","操作员"],
                ["category","活动类型"]]
        }]

     this.receiveStore = new Ext.data.Store({
            proxy: new Ext.data.HttpProxy({
                url: __ctxPath + "/plan/Plan!listPlan.action"
            }),
    }

    this.gridPanel = new Ext.grid.GridPanel({
            id: "PlanCarGrid",
            height: 330,
            store: this.receiveStore,
            shim: true,
            trackMouseOver: true,
            disableSelection: false,
            autoScroll: true,
            loadMask: true,
            cm: a,
            sm: b,
            viewConfig: {
                forceFit: true,
                enableRowBody: false,
                showPreview: false
            },
--------------------    分页 --------------------------------------
            bbar: new HT.PagingBar({
                pageSize: 25,
                store: this.receiveStore
            })
        });
});

JScript code

bbar: new HT.PagingBar({
                pageSize: 25,
                store: this.receiveStore,
                params : {
                  selectType : Ext.getCmp('plan.car.selectType').getValue()
                }
            })