input: Write a function to crawl a website for a specific type of data, such as phone numbers. If the website is reachable, the function should return a list of phone numbers found on the website. If no phone numbers are found or the website is not reachable, return an empty list.
  
  ### Function Header:
  
  def crawl_website_for_phone_numbers(website):
  
  
  ### Test Cases:
  
  assert crawl_website_for_phone_numbers('www.example.com')==['123-456-7890']
  assert crawl_website_for_phone_numbers('www.anothersite.com')==[]
  assert crawl_website_for_phone_numbers('www.phonesite.com')==['111-222-3333', '444-555-6666']
  assert crawl_website_for_phone_numbers('www.nonexistentsite.com')==[]
  
output: def crawl_website_for_phone_numbers(website):
      import requests
      import re
      try:
          response = requests.get(f'http://{website}')
          if response.status_code == 200:
              phone_numbers = re.findall(r'\b\d{3}[-.]?\d{3}[-.]?\d{4}\b', response.text)
              return phone_numbers
          else:
              return []
      except:
          return []