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
control = children[children.length - 1];
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.designer.ui.editors.IReportEditorPage#markPageStale(int)
	 */
	public void markPageStale(int type) {
		staleType = type;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.designer.ui.editors.IReportEditorPage#getStaleType()
	 */
	public int getStaleType() {
		return staleType;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.part.EditorPart#isDirty()
	 */
	public boolean isDirty() {
		return false;
	}
	protected IReportProvider getProvider() {
		IReportProvider provider = (IReportProvider) editor
				.getAdapter(IReportProvider.class);
		if (provider == null) {