ExtJS combobox won't reload store after submittinig another form

I have a combobox and a form window opening on the same page. The combobox code is:

combo1 = new Ext.form.ComboBox({
    fieldLabel: 'Intrested in',
    hiddenName: 'interest',
    store: new Ext.data.Store({
        proxy: new Ext.data.HttpProxy({
            url: 'ajax.php',
            method: 'GET'
        }),
        reader: new Ext.data.JsonReader({
            root: 'rows',
            fields: [{
                name: 'myId'
            }, {
                name: 'displayText'
            }]
        })
    }),
    valueField: 'myId',
    displayField: 'displayText',
    triggerAction: 'all',
    emptyText: 'Select',
    selectOnFocus: true,
    editable: false
});    

First time the list fetched from SQL table is loaded correctly.

On the same page there is a window with a short form submitting new values to sql database, but after submitting it and opening the combobox, the list is not refreshed.

ONLY after submitting the form again I can see the previously added values.

Why doesn't the combobox reload automatically after the开发者_Go百科 first submitting?

The problem here is, that the combobox internally caches the so called "last query" - if that doesn't change it does not reload its data from the store. So the solution is to reset this "last query" parameter:

combo1.lastQuery = null;