Merge branch 'bug/15/arr-undef' into 'master'

Resolve #15 replace flawed variable to avoid the ReferenceError

Closes #15

See merge request !10

script.js

@@ -61,7 +61,7 @@ function create_random_sid() {
   alphabet = "0123456789abcdefghjklmnopqrstuvwxyz";
   var ans = ''; 
   for (var i = 8; i > 0; i--) { 
-    ans +=  alphabet[Math.floor(Math.random() * arr.length)]; 
+    ans +=  alphabet[Math.floor(Math.random() * ans.length)]; 
   } 
   return ans; 
-} 
\ No newline at end of file
+}