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
fListViewerAdapter= new ListViewerAdapter();
		fParentElement= this;
		fElements= new ArrayList(10);
					
		fButtonLabels= buttonLabels;
		if (fButtonLabels != null) {
			int nButtons= fButtonLabels.length;
			fButtonsEnabled= new boolean[nButtons];
			for (int i= 0; i < nButtons; i++) {
				fButtonsEnabled[i]= true;
			}
		}	
				
		fTable= null;
		fTableControl= null;
		fButtonsControl= null;
		fTableColumns= null;
		
		fRemoveButtonIndex= -1;
		fUpButtonIndex= -1;
		fDownButtonIndex= -1;
	}
		
	/**
	 * Sets the index of the 'remove' button in the button label array passed in the constructor.
	 * The behaviour of the button marked as the 'remove' button will then be handled internally.
	 * (enable state, button invocation behaviour)
	 */	
	public void setRemoveButtonIndex(int removeButtonIndex) {
		Assert.isTrue(removeButtonIndex < fButtonLabels.length);