Bug 27491 Cannot add classpath variable to project
build id : 200212020010 The buttons OK and extend... are always disabled in the add variable dialog
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/dialogfields/ListDialogField.java
fElements.add(element);
		if (fTable != null) {
			fTable.add(element);
		}
		dialogFieldChanged();
	}
	/**
	 * Adds elements at the end of the list.
	 */	
	public void addElements(List elements) {
		int nElements= elements.size();
		
		if (nElements > 0) {
			
			ArrayList elementsToAdd= new ArrayList(nElements);
			
			for (int i= 0; i < nElements; i++) {
				Object elem= elements.get(i);
				if (!fElements.contains(elem)) {
					elementsToAdd.add(elem);
				}	
			}
			fElements.addAll(elementsToAdd);
			if (fTable != null) {
				fTable.add(elementsToAdd.toArray());
			}
			dialogFieldChanged();
		}
	}	
	/**