[VKS]

var myFormPanel = new Ext.form.FormPanel({
    title: 'Client and routing info',
    items: [{
        fieldLabel: 'Client',
        name: 'clientName'
    }, {
        fieldLabel: 'Port of loading',
        name: 'portOfLoading'
    }, {
        fieldLabel: 'Port of discharge',
        name: 'portOfDischarge'
    }]
});

myFormPanel.getForm().load({
    url: '/getRoutingInfo.php',
    params: {
        consignmentRef: myConsignmentRef
    },
    success : function(form, action) {
        Ext.Msg.alert("Load sucess", action.response.responseText);
    },
    failure: function(form, action) {
        Ext.Msg.alert("Load failed", action.response.errorMessage);
    }
});

Проверяй с помощью success и failure