extjs 怎样判断 grid 有修改过

grid.on('edit' , function(editor , e){
var month = Ext.util.Format.date(Ext.getCmp("month").getValue(), 'Y-m')+'-01';
Ext.Ajax.request({
url: "qam_metricsdata_post.cgi?project_id=[% project_id %]&type=grid&month="+month,
params:{

requirement_coverage : store_grid.findRecord("name2","Requirement Coverage By Testing").get("value2"),
ontime_delivery_rate : store_grid.findRecord("name1","On Time Delivery Rate").get("value1"),
//requirement_change_number : store_grid.findRecord("name2","Requirement Coverage By Testing").get("value2"),
iteration_number : store_grid.findRecord("name1","Number of iteration (Drop, Sprint)").get("value1"),
unit_test_model_code_coverage : store_grid.findRecord("name2","Unit Test Code Coverage – Model").get("value2"),
unit_test_handwritten_code_coverage : store_grid.findRecord("name2","Unit Test Code Coverage – Handwritten").get("value2"),
total_VERY_GOOD_check_points : store_grid.findRecord("name2","Total “very good” check points in quality gate").get("value2"),
quality_gate_compliance : store_grid.findRecord("name1","Quality Gate Compliance").get("value1"),
process_maturity : store_grid.findRecord("name2","Process Maturity").get("value2")

},
success: function(response, opts) {
Ext.toast.msg('Congratulations', 'Save Success!');
},
failure: function(response, opts) {
alert("Save Failed!");
}
});
});