Override existing $ function, fixed a few event module issues

README.md

@@ -18,13 +18,13 @@ Browser support: IE8+, Latest versions of Firefox, Chrome, Safari, Opera
 
 	functions:
 		
-		* Get: 
-			Use:
-			    $_.get(url, data_object, callback);
-		
-		* Post:
-			Use:
-			    $_.post(url, data_object, callback);
+	* Get: 
+		Use:
+		    $_.get(url, data_object, callback);
+	
+	* Post:
+		Use:
+		    $_.post(url, data_object, callback);
 			
 **QS**: querystring parsing and serialization for hashbang strings, and pushState urls
 	

kis.js

@@ -26,7 +26,7 @@
 		return (x.length === 1) ? x[0] : x;
 	};
 	
-	window.$ = window.$ || $;
+	window.$ = $;
 	
 	/**
 	 * Ajax 
@@ -272,6 +272,8 @@
 	 		add: function(sel, event, callback)
 	 		{
 	 			var i,len;
+	 			
+	 			if(!sel){return false;}
 	 		
 	 			if(sel.length)
 	 			{
@@ -290,6 +292,8 @@
 	 		{
 	 			var i, len;
 	 			
+	 			if(!sel){return false;}
+	 			
 	 			if(sel.length)
 	 			{
 	 				len = sel.length;