Bug 130068 [Regression]Report Parameter window doesn't pop up when preview a report with parameter.
Description: Report Parameter window doesn't pop up when preview a report with parameter. Steps to reproduce: 1. New a report parameter without default value. 2. Drag it to Layout. 3. Click Preview in Layout. Expected result: Window pops up for value input. Actual result: Some required parameter values are not set or set to incompatible data type.
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;
	/* (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 ( getEditorInput( ) != prePage.getEditorInput( ) )
		{
			setInput( prePage.getEditorInput( ) );
		}
		if ( prePage.isDirty( ) )
		{
			prePage.doSave( null );
		}
		if ( getBrowser( ) != null )
		{
			display( );
		}