v4.0.1

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "zenscroll",
-	"version": "4.0.0",
+	"version": "4.0.1",
 	"description": "A module to smooth-scroll web pages and scrollable elements (like DIVs)",
 	"main": "zenscroll.js",
 	"files": ["zenscroll.js", "zenscroll-min.js"],

zenscroll.js

@@ -1,8 +1,8 @@
 /**
- * Zenscroll 4.0.0
+ * Zenscroll 4.0.1
  * https://github.com/zengabor/zenscroll/
  *
- * Copyright 2015–2017 Gabor Lenard
+ * Copyright 2015–2018 Gabor Lenard
  *
  * This is free and unencumbered software released into the public domain.
  * 
@@ -58,7 +58,7 @@
 
 	// Detect if the browser already supports native smooth scrolling (e.g., Firefox 36+ and Chrome 49+) and it is enabled:
 	var isNativeSmoothScrollEnabledOn = function (elem) {
-		return ("getComputedStyle" in window) &&
+		return elem && "getComputedStyle" in window &&
 			window.getComputedStyle(elem)["scroll-behavior"] === "smooth"
 	}
 
@@ -177,6 +177,7 @@
 		 * @param {elem} The element.
 		 * @param {duration} Optionally the duration of the scroll operation.
 		 * @param {offset} Optionally the offset of the top of the element from the center of the screen.
+		 *        A value of 0 is ignored.
 		 * @param {onDone} An optional callback function to be invoked once the scroll finished.
 		 */
 		var scrollToCenterOf = function (elem, duration, offset, onDone) {