code: public boolean performCancel()
  	{
  		try
  		{
  			if (getBreakpoint().getMarker().getAttribute(ATTR_DELETE_ON_CANCEL) != null)
  			{
  				// if this breakpoint is being created, delete on cancel
  				getBreakpoint().delete();
  			}
  		} catch (CoreException e)
  		{
  			// JDIDebugUIPlugin.statusDialog(PropertyPageMessages.JavaBreakpointPage_9, e.getStatus());
  		}
  		return super.performCancel();
  	}
docs: Check to see if the breakpoint should be deleted.