[SOLVED] How to focus combobox?

Bookit.combo.UserList = function(config) {
    config = config || {};
    Ext.applyIf(config,{
        id: 'bookit-extra-userlist-live',
        name: 'user',
        hiddenName: 'user',
        url: Bookit.config.connectorUrl,
    	baseParams: { action: 'mgr/bookit/extra/getUsers' },
		minChars: 1,
		fields: ['id','fullname'],
		displayField:'fullname',
		valueField: 'id',
		forceSelection: false,
        typeAhead: true,
        selectOnFocus:true,
        loadingText: _('bookit.searching'),
        mode: 'remote',
        editable: true,
        triggerAction: 'all',
        emptyText: _('bookit.fillName')
    });
    Bookit.combo.UserList.superclass.constructor.call(this,config);
};
Ext.extend(Bookit.combo.UserList,MODx.combo.ComboBox);
Ext.reg('bookit-extra-userlist-live',Bookit.combo.UserList);
	

Bookit.window.NewBook = function(config) {
    config = config || {};
    Ext.applyIf(config,{
        id: 'bookit-window-newbook'
        ,title: _('bookit.newBook')
        ,url: Bookit.config.connectorUrl
        ,baseParams: { 
        	action: 'mgr/bookit/board/saveBook'
        }
        ,fields: [{
            focus: true
            ,xtype: 'bookit-extra-userlist-live'
            ,fieldLabel: _('bookit.fullname')
            ,name: 'fullname'
            //,id: 'userlist'
            ,width: 300
            ,listeners: {
                'select': {fn:this.testuj,scope:this}
            }
        },{
            xtype: 'textfield'
            ,fieldLabel: _('bookit.phone')
            ,name: 'phone'
            ,width: 300
        },{
            xtype: 'textfield'
            ,fieldLabel: _('email')
            ,name: 'email'
            ,width: 300
        },{
            xtype: 'bookit-extra-combo-items'
            ,fieldLabel: _('bookit.item')
            ,name: 'item'
            ,width: 300
        },{
            xtype: 'timefield'
            ,fieldLabel: _('bookit.time')
            ,format: MODx.config.manager_time_format
            ,increment: 60
            ,minValue: '7:00'
            ,maxValue: '21:00'
            ,name: 'time'
            ,width: 300
        },{
            xtype: 'numberfield'
            ,fieldLabel: _('bookit.hourCount')
            ,id: 'count'
            ,name: 'count'
            ,minValue: 1
            ,enableKeyEvents:true
            ,maxValue: 15
            ,width: 300
            ,listeners:{
            	keyup:function(field, e){
                	Ext.getCmp('sliderCount').setValue(parseInt(field.getRawValue()));
                }
            }
        },{
            xtype: 'sliderfield'
            ,name: 'sliderCount'
            ,id: 'sliderCount'
            ,useTips: false
            ,minValue: 1
            ,maxValue: 15
            ,increment: 1
            ,width: 300
            ,scope: this
            
        }]
        ,buttons: [{
            text: config.cancelBtnText || _('cancel')
            ,scope: this
            ,handler: function() { this.close(); }
        },{
            text: config.saveBtnText || _('save')
            ,scope: this
            ,handler: this.submit
        }]
    });
    Bookit.window.NewBook.superclass.constructor.call(this,config);
    Ext.getCmp('sliderCount').slider.on('change', function(slider,newvalue,oldvalue){Ext.getCmp('count').setValue(newvalue);});
};
Ext.extend(Bookit.window.NewBook,MODx.Window, {
	testuj: function() {
		var userid = Ext.getCmp('bookit-extra-userlist-live').value
		var newBookWindow = this;
		MODx.Ajax.request({
            url: Bookit.config.connectorUrl
            ,params: {
                action: 'mgr/bookit/board/getUserDetails'
                ,id: userid
            }
	        ,listeners: {
	            'success': {fn:function(r) {		    			        
	            	newBookWindow.setValues(r.object);
	            },scope:this}
	        }
        });
		//this.setValues([{id:'email', value:'[email protected]'}])
		//Ext.getCmp('bookit-extra-combo-items').setValue(2);
    }
	
});
Ext.reg('bookit-window-newbook',Bookit.window.NewBook);

Ext.getCmp('bookit-extra-userlist-live').focus()
TypeError: Property 'focus' of object [object Object] is not a function
Ext.getCmp('bookit-extra-userlist-live').focus('', 10)
TypeError: Property 'focus' of object [object Object] is not a function

	this.on('show', function(){
		var task = new Ext.util.DelayedTask(function(){
			this.fp.getForm().el.dom[1].select();
		}, this);
		task.delay(200); 
	});