Ext.onReady(function(){

    var dataStore = new Ext.data.Store({

//        proxy: new Ext.data.HttpProxy({url: 'sampledata-sheldon.xml'}),
        proxy: new Ext.data.ScriptTagProxy({url: 'http://www.sofsis.cl/sampledata-sheldon.xml'}),

        reader: new Ext.data.XmlReader({
               record: 'Item',
               id: 'ASIN'
           }, [
               'Author', 'Title', 'Manufacturer', 'ProductGroup'
           ])
    });

    var colModel = new Ext.grid.ColumnModel([
	    {header: "Author", width: 120, dataIndex: 'Author'},
		{header: "Title", width: 180, dataIndex: 'Title'},
		{header: "Manufacturer", width: 115, dataIndex: 'Manufacturer'},
		{header: "Product Group", width: 100, dataIndex: 'ProductGroup'}
	]);

    var grid = new Ext.grid.Grid('mygrid', {
        ds: dataStore,
        cm: colModel,
	trackMouseOver: true
    });
    grid.render();
    dataStore.load();
});