I am trying to handle a click event on the line chart. The sequence of events should be
1. Display A line chart
2. Click on a point
3. grab the related parameterts
4. Pass these parameters to the server and display the grid with the detailed information.

My problem is in Step 4. My request is not sent to the server. Can someone tell me where I can be wrong.

Code:
new Ext.Button({
      text: 'Display Chart',
      renderTo: 'chartButton',
      handler: function() {       
      LoadAndShowChart(); 
      }
      
    });
    
    var chartstore = new Ext.data.JsonStore(
    {         
            url: '/ext/testServlet',
            root: 'chart.data',            
            baseParams: {'action': 'fetchChartData'},    
            fields: [
                   ,{name: 'color', type: 'string'}
                   ,{name: 'lots', type: 'int'}
                   ,{name: 'alias', type: 'string'}                                         
                ]        

    });
    
 var linecht = new Ext.Panel({
        iconCls:'chart',
        title: 'ExtJS.com',
        frame:true,
        width:600,
        height:300,
        layout:'fit',
        items: {
            xtype: 'linechart',
            store: chartstore,
            xField: 'alias',
            yField: 'lots',
            listeners: {
              itemclick: function(o){
              var rec = chartstore.getAt(o.index);
              refreshGrid(rec.get('alias'),
                        --------and other parameters here.
             }
          }            
        },
         url:'../../resources/charts.swf'                  

    });

    var datastore = new Ext.data.JsonStore({
            url: '/ext/testServlet',
            root: 'flowers.data',
            id: 'flowerId',                
            totalProperty: 'flowers.totalRows',
            baseParams: {'action': 'listFlowers'},    
            fields: [
                --- All the fields here                                            
                ]        
            });
   var grid = new Ext.grid.GridPanel( {
     store: datastore
        -- other grid configuration
    })
   
function refreshGrid(-- all parameters are included here -- ){        
    // render the grid
    grid.render(document.getElementById('tradeGrid'));
    alert( ) ; -- this prints all the parameters
       // configure callback  
    grid.getStore().on('load', loadSuccessful);
    // load the store            
    alert("loading the store now "); -- This comes up
        grid.getStore().load({params: {'fetchfromDb': fetchDb,
                                       'alias':alias,
                                        -- all other params here
                                        start:0, limit:25                                          
                                        }});
      -- The above load statement does not send a request- Where is the problem
      -- as a result the grid is empty.
}