Bug 180864 Change Allow Null option in Cascading Group.[0705]
Description: Change Allow Null option in Cascading Group. Build number:2.2.0.v20070404 Steps to reproduce: 1. New a cascading group and add sub parameter. Expected result: Is Required option in cascading group definition dialog. Actual result: Allow null value option in Cascading Group definition dialog Error log:N/A
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
value = parameter.getName( );
				}
				else if ( COLUMN_DATA_SET.equals( property ) )
				{
					if ( isSingle( )
							&& inputParameterGroup.getDataSet( ) != null )
					{
						value = inputParameterGroup.getDataSet( ).getName( );
					}
					else if ( getDataSet( parameter ) != null )
					{
						value = getDataSet( parameter ).getName( );
					}
				}
				else if ( COLUMN_VALUE.equals( property ) )
				{
					value = getColumnName( parameter, COLUMN_VALUE );
				}
				else if ( COLUMN_DISPLAY_TEXT.equals( property ) )
				{
					value = getColumnName( parameter, COLUMN_DISPLAY_TEXT );
				}
				if ( value == null )
				{
					value = ""; 
				}
				return value;
			}
			return ""; 
		}