Bug 153412 Change parameter type will cause preview fail
Description: Change parameter type will cause preview fail Steps to reproduce: 1. New a report paramter, string, text-box, default value is abc. 2. Drag the parameter to Layout and preview. 3. Change the parameter's type to integer, list-box, add a value 1 4. Preview Expected result: No errors. Actual result: The value "abc" is invalid with the type "integer".
UI/org.eclipse.birt.report.designer.ui.preview/src/org/eclipse/birt/report/designer/ui/preview/editors/ReportPreviewFormPage.java
{
			return ( (ModuleHandle) getModel( ) ).needsSave( );
		}
		return false;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.forms.editor.IFormPage#getPartControl()
	 */
	public Control getPartControl( )
	{
		return control;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.forms.editor.IFormPage#getId()
	 */
	public String getId( )
	{
		return ID;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.IWorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
	 */
	public void createPartControl( Composite parent )
	{