Bug 141255 No error for the incompatible parameter value
Steps to reproduce: 1.New a decimal parameter, set the default value to "aaa" 2.Preview the report by "Preview" tab Expected result: Error to say the incompatible parameter value Actual result: Parameter request page keeps poping up till input the decimal value Note: if preview in Web Viewer, error will be thrown out, but no exception description.
UI/org.eclipse.birt.report.designer.ui.preview/src/org/eclipse/birt/report/designer/ui/preview/editors/ReportPreviewFormPage.java
* (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 )
		{
			provider = super.getProvider( );
		}
		return provider;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.part.WorkbenchPart#getAdapter(java.lang.Class)
	 */
	public Object getAdapter( Class adapter )
	{
		if ( adapter.equals( ActionRegistry.class ) )
		{
			return new ActionRegistry( );
		}
		return super.getAdapter( adapter );