title: Javascript: validation for mobile number with paste option
body: <p>I am working in Javascript. I am trying to make a function on the <code>keypress</code> event. I want to make function for validation on mobile number. I want to allow only digits in it. I also want to allow <em>ctrl+v</em> and <em>ctrl+a</em> in this but I dont want to allow V and A as characters.</p>
  
  <p>I have seen many answers here but no one is purely same.</p>