Clear textbox after click on reset button using angularjs

Hello,

 

I am creating on form using ASP.Net MVC and AngularJS. I have one textbox which is mandatory, one submit button and one clear button. If textbox remains blank and I clicked on submit button then textbox border color get red.But when I clicked on reset button I want to clear textbox button and remove border color. I have attached my code and snap.

 

Please give me solution