final XulGrid stepGrid = (XulGrid) mainWizardContainer.getDocumentRoot().getElementById(STEP_GRID_ID);
// grab the rows and add a new row to it
final XulRows stepRows = (XulRows) mainWizardContainer.getDocumentRoot().getElementById(STEP_ROWS_ID);
final XulRow stepRow = (XulRow) mainWizardContainer.getDocumentRoot().createElement(XUL_ROW_TYPE);
stepRows.addChild(stepRow);
// Create and add the activeImage to the row (goes in the first column)
stepImage = (XulImage) mainWizardContainer.getDocumentRoot().createElement(XUL_IMAGE_TYPE);
stepImage.setSrc(STEP_IMAGE_SRC);
stepImage.setId(this.getStepName());