How to Deselect options in Listbox

Webdriver driver=new FirefoxDriver();

driver.get("https://www.facebook.com/");

WebElement box=driver.findElement(By.id("month"));

Select sel=new Select(box);

sel.deselectbByValue("Jul");

sel.deselectByVisibleText("Aug");

sel.deselectByindex(5);

sel.deselectAll();

}