How to move JavaScript functions out of the global namespace when used with Visualforce chart components

PieChartRemoteDemo.page

<apex:page controller="PieChartRemoteController">
    <script>
    var noData = new Object();  // Simply a dummy placeholder for data attribute
    var App = App || {}; // To hold functions
    
    App.retrieveChartData = function(callback) {
       var year = document.getElementById('theYear').value;
       Visualforce.remoting.Manager.invokeAction(
           '{!$RemoteAction.PieChartRemoteController.getRemotePieData}',
           year,
           function(result, event) {
               if(event.status && result && (result.constructor === Array)) {
                   callback(result);
                   myc.RemotingPieChart.show();
               }
               else if (event.type === 'exception') {
                   document.getElementById("remoteResponseErrors").innerHTML = event.message + 
                       '<br/>' + event.where;
               }
               else {
                   document.getElementById("remoteResponseErrors").innerHTML = event.message;
               }                   
           },
           { escape: true }
       );
    };
    
    App.refreshRemoteChart = function() {
        var statusElement = document.getElementById('statusDisplay');
        statusElement.innerHTML = "loading...";
        App.retrieveChartData(function(statusElement){
                return function(data){
                    myc.RemotingPieChart.reload(data);
                    statusElement.innerHTML = '';
                };
            }(statusElement)
        );
    };
    </script>

    <apex:pageBlock title="Charts">

        <apex:pageBlockSection title="Visualforce Charting + JavaScript Remoting">
			
            <!-- Please note that the data attribute in this example
                 can be thought of as simply providing a default or initial value.
                 
				 Subsequent calls to RemotePieChart.reload(data) effectively
                 override whatever is specified in the element's data attribute.
                 
                 This means that whatever you specify in the data attribute
                 won't matter if you simply call the refresh function. -->
            <apex:chart height="350" width="450" data="noData" 
                name="RemotingPieChart" hidden="true">
                <apex:pieSeries dataField="data" labelField="name"/>
                <apex:legend position="right"/>
            </apex:chart>
            
            <div>
                <select id="theYear" onChange="App.refreshRemoteChart();">
                    <option value="2013">2013</option>
                    <option value="2012">2012</option>
                    <option value="2011">2011</option>
                    <option value="2010">2010</option>
                </select>
                <span id="statusDisplay"></span>
                <span id="remoteResponseErrors"></span>
            </div>

        </apex:pageBlockSection>

    </apex:pageBlock>
    
    <script>
    // Initiate the refresh action to populate the chart
    App.refreshRemoteChart();
    </script>
</apex:page>