diplayaing check box in the LOV of combo box

Hi...

Here i created a combo box with check boxes....

It's displaying properly..

But In combo_check1.PNG..

just am clicking on the particular value then value not on check box its displaying value on the combo box but

check box is not selecting..

after that

if click on check box then value are removing from the combo box(combo_check_box2.PNG).

This issue am facing.

Here is my code of combo box...

{

xtype: 'combobox', //9

fieldLabel: 'Combobox',

labelAlign:'right',

displayField: 'name',

multiSelect:true,

tpl:new Ext.XTemplate('<tpl for=".">',

'<div class="x-boundlist-item">',

'<input type="checkbox" />',

'{name}',

'</div>',

'</tpl>'

),

store: Ext.create('Ext.data.Store', {

fields: [{

type: 'string',

name: 'name'

}],

data: [{

"name": "Alabama"

}, {

"name": "Alaska"

}, {

"name": "Arkansas"

}, {

"name": "California"

}]

}),

queryMode: 'local'

}

Help me in this...

Thanks In Advance

Kamalakar Reddy

diplayaing check box in the LOV of combo box