I have an extended combobox (as below) simply for reuse in multiple windows. In the failure property of the store I need to know which window was attempting to display the combobox. Any reference is fine, even just the window id or name. Suggestions? Thanks.

studycbx = Ext.extend(Ext.form.ComboBox, {
displayField: 'StudyName',
editable: false,
emptyText: 'Select a Study...',
fieldLabel: 'Study',
forceSelection: true,
mode: 'remote',
selectOnFocus: true,
store: new Ext.data.Store({
baseParams: { querytype: 'select', queryname: 'study' },
proxy: new Ext.data.HttpProxy({
method: 'POST',
url: 'filepath',
failure: function(response) {
// need to know which window here
reader: new Ext.data.JsonReader( { root: '', id: 'StudyID' }, Study )
triggerAction: 'all',
valueField: 'StudyID',
width: 150
Ext.reg('studycomboxtype', studycbx);