JQuery Capitalize First Letter Of Each Word In A Sentence [duplicate]

I’m trying to capitalize first letter of each word from a text field using JQuery but unfortunately I’m unable to.

Below is the Bootstrap code I currently have to get data from a text field from a submitted button

<button class="btn btn-primary" type="button" id="btn4" value="alternatingCase">Alternating Case</button>

Below JQuery code converts only the first letter of the paragraph to caps

$("#btn4").click(function(){
  var input = $("#input1");
  input.val(input.val().charAt(0).toUpperCase() + input.val().substr(1).toLowerCase());
  });