Is it possible to use form.Action.Submit with a RowEditor? I want to be able to do something like this:

var myEditor = new Ext.ux.grid.RowEditor({saveText: 'Update', listeners: {afteredit: saveEdits}});
myGrid = new Ext.grid.GridPanel({
    plugins: [ editor ],

function saveEdits() {
    if( myEditor.form.isValid() ) {
            url: 'actions.php',
            waitMsg: 'Please wait...',
            params: {task: 'UPDATE'},
            success: successHandler,
            failure: failureHandler
    } else {
        Ext.MessageBox.alert( 'Warning', 'Your form is not valid!' );
...but I'm getting an "undefined" error on myEditor.form. What am I missing, or is this even possible?