Bug 140538 Can't save by auto when it is preview after create the 2nd parameter
Details: Can't save by auto when it is preview after create the 2nd parameter Step: 1.New a report design. 2.Create the 1st parameter and preview. 3.Create the 2nd parameter and preview. Actual result: After step 2, it is ok. After step 3, if I have not press save button, it will not save by auto.
UI/org.eclipse.birt.report.designer.ui.preview/src/org/eclipse/birt/report/designer/ui/preview/editors/ReportPreviewFormPage.java
IReportEditorPage {
	public static final String ID = "BIRT.Preivew"; 
	private Control control;
	private int staleType;
	private FormEditor editor;
	
	public static final String SUFFIX_DESIGN_FILE = "rptdesign"; 
	
	
	public static final String SUFFIX_DESIGN_CONFIG = "rptconfig"; 
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.designer.ui.editors.IReportEditorPage#onBroughtToTop(org.eclipse.birt.report.designer.ui.editors.IReportEditorPage)
	 */
	public boolean onBroughtToTop(IReportEditorPage prePage) {
		if (this.isMissingParameter()) {
			if (this.parameterDialog != null) {
				this.parameterDialog.open();
			}
			return true;
		}
		if (getEditorInput() != prePage.getEditorInput()) {
			setInput(prePage.getEditorInput());
		}
		if (prePage.isDirty()) {
			prePage.doSave(null);