title: How to check If a Tel: area code is correct using jquery?
body: <p>Hy
  I need to check if the given phone area code is correct.
  i created a input field, user can insert a tel area code like <strong>0044</strong> oder <strong>0090</strong> and so on.
  I restricted the input field to 4 chars. 
  I need to check after the 4 chars are entered if the area code is correct.</p>
  
  <p><strong>What it should do.</strong>
  After entering <strong>4</strong> number, the script should check the following things.
  Does the entered number equals something like  <code>"00{number 2 digit only}"</code> if it doesnt <code>alert("please enter correct tel areacode");</code></p>
  
  <p>I hope i could explain my problem clear. 
  How can i do it with javascript or jquery?</p>