rewrite graph.js in coffeescript

app/assets/javascripts/graph.js

-function initGraphNav() { 
-  $(".graph svg").css("position", "relative");
-  $("body").bind("keyup", function(e) {
-    if(e.keyCode == 37) { // left
-      $(".graph svg").animate({ left: "+=400" });
-    } else if(e.keyCode == 39) { // right
-      $(".graph svg").animate({ left: "-=400" });
-    }
-  });
-}

app/assets/javascripts/graph.js.coffee

+initGraphNav = ->
+  $('.graph svg').css 'position', 'relative'
+
+  $('body').bind 'keyup', (e) ->
+    if e.keyCode is 37 # left
+      $('.graph svg').animate left: '+=400'
+    else if e.keyCode is 39 # right
+      $('.graph svg').animate left: '-=400'
+
+window.initGraphNav = initGraphNav