allowNull.setSelection( false );
	private void clearParamProperties( )	{		paramNameEditor.setText( "" ); //$NON-NLS-1$		promptText.setText( "" ); //$NON-NLS-1$		dataTypeChooser.select( -1 );		displayTypeChooser.select( -1 );		defaultValueEditor.setText( "" ); //$NON-NLS-1$		helpTextEditor.setText( "" ); //$NON-NLS-1$		formatField.setText( "" ); //$NON-NLS-1$		listLimit.setText( "" ); //$NON-NLS-1$		previewLable.setText( "" ); //$NON-NLS-1$	}