Javascrpirt in selenium

WebElement webElement = driver.findElement(By.xpath("xpath_element"));
JavascriptExecutor javaScriptExecutor = (JavascriptExecutor)driver;
javaScriptExecutor.executeScript("arguments[0].click()", webElement);

javaScriptExecutor.ExecuteScript("return jQuery.active == 0")

JavascriptExecutor js = (JavascriptExecutor)driver;
js.executeScript("return document.readyState").toString().equals("complete");