Case insensitive string filter in ext js
===

How can I make case insensitive string filter in extjs. Following is the corresponding grid column.

    var columns = [{
               dataIndex: 'name',
    		   header: 'NAME',
    		   style: 'border: none;',
    		   id: 'applicantname',
    		   sortable : true,
    		   width: 141,
    		   filter: {
    		       type: 'string'
    		   }
    	   }