Bug 146796 Error message pop up if display text contain non-digital char when add next item
Description: In decimal type parameter creation,display type is "list box", Error message pop up if "display text" contain non-digital char when add next item. Steps: 1.Create a new decimal parameter 2.Set display type as "list box" 3.Input one item: value:1, display text:test 4.Input another item: Value:2 Actual result: error message pop up: The display text already exists! Expected result: Input item succussfully.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
}
				else if ( COLUMN_DISPLAY_TEXT.equals( property ) )
				{
					choice.setLabel( newValue );
				}
			}
			refreshValueTable( );
		}
	};
	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 )
	{