元素不可点击以及如何检查必填字段

Question

 `i have "Add Driver" feature in that so many fields are there all are 
   mandatory..if i will not enter any data into fields ,it will display 
   "field is required message",,for this how can i write selenium script`.

     WebDriverWait wait2 = new WebDriverWait(driver, 20);
     wait2.until(ExpectedConditions.elementToBeClickable(By.xpath("//a[contains(text(),'Add Driver')]"))).click();

`below picture is an example,,] 1

i didn't get how to write logic i m new selenium help me..