title: how to do form validation for required fields in angular
body: <p>I want to validate my form by using Angular form validation.I have read many articles which give info on how to validate form before submitting. But My question is how can i validate form for required field
  e.g.  For my login form I have two fields One user name and Password. Without entering any field values ,user clicks on login button. So in this scenarion how to do validation in angular.</p>
  
  <p>Thanks in advance,</p>