Bug 190727 [regression]Default value issue when switch report parameter from textbox to listbox.[0705]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
				ExceptionHandler.handle( e );
			}
			displayTextChooser.removeAll( );
			displayTextChooser.add( NONE_DISPLAY_TEXT );
			for ( Iterator iter = columnList.iterator( ); iter.hasNext( ); )
			{
				displayTextChooser.add( ( (ResultSetColumnHandle) iter.next( ) ).getColumnName( ) );
			}
			displayTextChooser.setText( NONE_DISPLAY_TEXT );
		}
		String originalSelection = columnChooser.getText( );
		columnChooser.removeAll( );
		for ( Iterator iter = columnList.iterator( ); iter.hasNext( ); )
		{
			ResultSetColumnHandle cachedColumn = (ResultSetColumnHandle) iter.next( );
			if ( matchDataType( cachedColumn ) )
			{
				columnChooser.add( cachedColumn.getColumnName( ) );
			}
		}
		if ( columnChooser.indexOf( originalSelection ) != -1 )
		{
			columnChooser.setText( originalSelection );
		}
		
		
		
		
		columnChooser.setEnabled( columnChooser.getItemCount( ) > 0 );