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
newControlType = DesignChoiceConstants.PARAM_CONTROL_LIST_BOX;
							selectedParameter.setMustMatch( true );
						}
						else if ( PARAM_CONTROL_LIST.equals( newControlType ) )
						{
							newControlType = DesignChoiceConstants.PARAM_CONTROL_LIST_BOX;
							selectedParameter.setMustMatch( false );
						}
						else
						{
							selectedParameter.setProperty( ScalarParameterHandle.MUCH_MATCH_PROP,
									null );
						}
						selectedParameter.setControlType( newControlType );
					}
					catch ( SemanticException e1 )
					{
						ExceptionHandler.handle( e1 );
					}
				}
			}
		} );
		createLabel( propertiesGroup, LABEL_DEFAULT_VALUE );
		defaultValueEditor = new Text( propertiesGroup, SWT.BORDER );
		defaultValueEditor.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
	}
	private void createOptionsPart( Composite parent )
	{
		optionsGroup = new Group( parent, SWT.NULL );
		optionsGroup.setText( LABEL_GROUP_MORE_OPTIONS );