Bug 135465 [smoke]An error occurred when new a casading Parameter
Description: An error occurred when new a casading Parameter Step to reproduce: 1.new a sample db data source and data set 2.New a cascading parameter group, named "gp1", 3.select the data set, then create two cascading parameters, one is row["customernumber"], named p1; the other is row["customername"] Actual result; error message occurred repeatly
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
loading = false;
	}
	private void clearParamProperties( )
	{
		paramNameEditor.setText( "" ); 
		promptText.setText( "" ); 
		dataTypeChooser.select( -1 );
		displayTypeChooser.select( -1 );
		defaultValueEditor.setText( "" ); 
		helpTextEditor.setText( "" ); 
		formatField.setText( "" ); 
		listLimit.setText( "" ); 
		previewLable.setText( "" ); 
		allowNull.setSelection( false );
	}
	private void setControlEnabled( boolean enable )
	{
		paramNameEditor.setEnabled( enable );
		promptText.setEnabled( enable );
		dataTypeChooser.setEnabled( enable );
		displayTypeChooser.setEnabled( enable );
		defaultValueEditor.setEnabled( enable );
		helpTextEditor.setEnabled( enable );
		formatField.setEnabled( enable );
		listLimit.setEnabled( enable );
		changeFormat.setEnabled( enable );
	}
	private void changeDataType( String type )
	{
		initFormatField( type );