application.js

function eval_tags (){
	tags = $('#tags').val()
	$.get("/tags/usertags/", $('#tags').val())
	.done(function() {
		alert( "second success" );
	})
	.fail(function() {
		alert( "error" );
	})
	.always(function() {
		alert( "finished" );
	});

	console.log(tags + count);
	count++;
}

routes.rb

  get "tags/usertags/:tags", to: 'tags#usertags', as: 'usertags'