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
/**
	 * Sets the elements shown in the list.
	 */
	public void setElements(List elements) {
		fElements= new ArrayList(elements);
		if (fTable != null) {
			fTable.refresh();
		}
		dialogFieldChanged();
	}
	/**
	 * Gets the elements shown in the list.
	 * The list returned is a copy, so it can be modified by the user.
	 */	
	public List getElements() {
		return new ArrayList(fElements);
	}
	/**
	 * Gets the elements shown at the given index.
	 */		
	public Object getElement(int index) {
		return fElements.get(index);
	}
	
	/**
	* Gets the index of an element in the list or -1 if element is not in list.
	*/
	public int getIndexOfElement(Object elem) {
		return fElements.indexOf(elem);
	}