fixing issue #1159

Author: tomahim

Source/Drag/Drag.js

@@ -46,6 +46,7 @@ var Drag = this.Drag = new Class({
 		limit: false,
 		handle: false,
 		invert: false,
+		unDraggableTags: ['button', 'input', 'a', 'textarea', 'select', 'option'],
 		preventDefault: false,
 		stopPropagation: false,
 		compensateScroll: false,
@@ -133,6 +134,10 @@ var Drag = this.Drag = new Class({
 	},
 
 	start: function(event){
+		if (
+			this.options.unDraggableTags.contains(event.target.get('tag'))
+		) return;
+		
 		var options = this.options;
 
 		if (event.rightClick) return;