[GeoNetwork-users] getWhen() causes a problem in map icon

GeoNetwork GeoNetwork User
1

Normally, I have a square icon on top of the map to select an area. However, after I simplified the function 'getWhen' to a backbone piece as below:
getWhen: function(){
var anyTime = new Ext.form.Checkbox({
name: 'timeType',
checked: true,
fieldLabel: OpenLayers.i18n('anyTime'),
hidden: true
});

    var items = \[anyTime\];
    items\.push\(GeoNetwork\.util\.SearchFormTools\.getTemporalExtentField\(anyTime\)\);

    return items;
\},

I found the square icon on the map toolbar mysteriously is gone. no error is found in Firebug. any one could give me some clue how this simplified getWhen() would affect the functionality of the map?
Thank you a ton in advance.
Steve