Radio button in ng-grid with check & uncheck options

<!DOCTYPE html>
<html ng-app="myApp">

<head lang="en">
  <meta charset="utf-8">
  <title>Custom Plunker</title>
  <link rel="stylesheet" type="text/css" href="http://angular-ui.github.com/ng-grid/css/ng-grid.css" />
  <link rel="stylesheet" type="text/css" href="style.css" />
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.2/angular.min.js"></script>
  <script type="text/javascript" src="http://angular-ui.github.com/ng-grid/lib/ng-grid.debug.js"></script>
  <script type="text/javascript" src="script.js"></script>
</head>

<body ng-controller="MyCtrl">
  <div class="gridStyle" ng-grid="gridOptions"></div>
</body>

</html>

// main.js
var app = angular.module('myApp', ['ngGrid']);
app.controller('MyCtrl', function($scope) {
    $scope.myData = [{id:1,name: "Moroni", age: 50},
                     {id:2,name: "Tiancum", age: 43},
                     {id:3,name: "Jacob", age: 27},
                     {id:4,name: "Nephi", age: 29},
                     {id:5,name: "Enos", age: 34}];
    $scope.gridOptions = { 
      data: 'myData',
      multiSelect: false,
      enableRowSelection: false,
       columnDefs : [{ 
                     field:'name', 
                     displayName:'Radio',
                     cellTemplate :'<div style="text-align:center"><input type="radio" name="ret" value="{{row.rowIndex}}" ng-click="uncheck($event,row)"></div>'
                   },
                   { 
                     field:'name', 
                     displayName:'Name'
                   },{ 
                     field:'age', 
                     displayName:'Age'
                   }]
   };
   
    $scope.uncheck = function (event,row) {
      var obj = event.target;
      if($(obj).attr('previousValue') == 'true'){
            $(obj).attr('checked', false);
        } else {
            $('input[name=ret]').attr('previousValue', false);
        }
        $(obj).attr('previousValue', $(obj).prop('checked'));
        //alert(row.getProperty('name'));
    };
    
   
});

/*style.css*/
.gridStyle {
    border: 1px solid rgb(212,212,212);
    width: 400px; 
    height: 300px
}

Radio button in Ng - Grid with check & uncheck options.