Bug 191685 [regression]Set default value doesn't work in Report Parameter[0705]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
changeDefaultValue( null );
				}
				choiceList.remove( elements[i] );
			}
			return true;
		}
	};
	private Text listLimit;
	/**
	 * Create a new parameter dialog with given title under the active shell
	 * 
	 * @param title
	 *            the title of the dialog
	 */
	public ParameterDialog( String title )
	{
		this( UIUtil.getDefaultShell( ), title );
	}
	/**
	 * Create a new parameter dialog with given title under the specified shell
	 * 
	 * @param parentShell
	 *            the parent shell of the dialog
	 * @param title
	 *            the title of the dialog
	 */
	public ParameterDialog( Shell parentShell, String title )
	{
		super( parentShell, title );
	}