Bug 200312 Chart Variables are still in the bottom right pane when select other categories [13]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ExpressionBuilder.java
if ( inputElement instanceof PropertyHandle
					|| inputElement instanceof TabularMeasureGroupHandle
					|| inputElement instanceof TabularDimensionHandle )
			{
				return EMPTY;
			}
			else if ( inputElement instanceof LevelHandle )
			{
				List childrenList = new ArrayList( );
				childrenList.add( inputElement );
				for ( Iterator iterator = ( (LevelHandle) inputElement ).attributesIterator( ); iterator.hasNext( ); )
				{
					childrenList.add( iterator.next( ) );
				}
				return childrenList.toArray( );
			}
			else if ( inputElement instanceof TabularMeasureHandle )
			{
				List childrenList = new ArrayList( );
				childrenList.add( inputElement );
				return childrenList.toArray( );
			}
			return provider.getChildren( inputElement );
		}
		private List getChildren( Object inputElement )
		{
			List childrenList = new ArrayList( );
			Object[] children = provider.getChildren( inputElement );
			childrenList.addAll( Arrays.asList( children ) );
			for ( int i = 0; i < children.length; i++ )