title: Angular 2 : Required Validation is not showing
body: <p>HTML :</p>
  
  <pre><code>&lt;input type="text" id="txtFName" formControlName="firstName" required/&gt;
  </code></pre>
  
  <p><code>&lt;input type="submit" id="btnSubmit" value="Submit" (click)="save()"/&gt;</code></p>
  
  <p>component.ts :</p>
  
  <pre><code>ngOnInit(){
      this.regForm=this.formBuilder.group({
          firstName:['', Validators.required],
          lastName:['', Validators.required],
          eMail:['', Validators.required],
          DOB:['', Validators.required]
      })
  }
  
      save():void
  {
      console.log(this.regForm.value);
  }
  </code></pre>
  
  <p>while clicking submit button, required validation is not arising.</p>
  
  <p>Please let me know what is needed to be done</p>