How to check whether a checkbox is checked or not in Ext JS 3 when 'name' attribute is used

I have checkboxes created in Ext JS. When defined with 'id' attribute, I'm able to check whether its checked or not, but this is resulting in a different functionality failure.

I want to check whether the checkbox is checked or not when those checkboxes are created using 'name' attribute instead of 'id' attribute.

Please help me