diff --git a/lib.nas b/lib.nas
index 7e85c8e..d17da21 100644
--- a/lib.nas
+++ b/lib.nas
@@ -8,6 +8,12 @@ var print=func(elements...)
     nasal_call_builtin_std_cout(elements);
     return nil;
 };
+var println=func(elements...)
+{
+    nasal_call_builtin_std_cout(elements);
+    print('\n');
+    return nil;
+}
 var append=func(vector,elements...)
 {
     nasal_call_builtin_push_back(vector,elements);
@@ -110,58 +116,22 @@ var io=
 
 var bits=
 {
-    bitxor:func(a,b)
-    {
-        return nasal_call_builtin_xor(a,b);
-    },
-    bitand:func(a,b)
-    {
-        return nasal_call_builtin_and(a,b);
-    },
-    bitor:func(a,b)
-    {
-        return nasal_call_builtin_or(a,b);
-    },
-    bitnand:func(a,b)
-    {
-        return nasal_call_builtin_nand(a,b);
-    },
-    bitnot:func(a)
-    {
-        return nasal_call_builtin_not(a);
-    }
+    bitxor:  func(a,b){return nasal_call_builtin_xor(a,b); },
+    bitand:  func(a,b){return nasal_call_builtin_and(a,b); },
+    bitor:   func(a,b){return nasal_call_builtin_or(a,b);  },
+    bitnand: func(a,b){return nasal_call_builtin_nand(a,b);},
+    bitnot:  func(a)  {return nasal_call_builtin_not(a);   }
 };
 
 var math=
 {
-    e:2.7182818284590452354,
-    pi:3.14159265358979323846264338327950288,
-    sin:func(x)
-    {
-        return nasal_call_builtin_sin(x);
-    },
-    cos:func(x)
-    {
-        return nasal_call_builtin_cos(x);
-    },
-    tan:func(x)
-    {
-        return nasal_call_builtin_tan(x);
-    },
-    exp:func(x)
-    {
-        return nasal_call_builtin_exp(x);
-    }, 
-    ln:func(x)
-    {
-        return nasal_call_builtin_cpp_math_ln(x);
-    },
-    sqrt:func(x)
-    {
-        return nasal_call_builtin_cpp_math_sqrt(x);
-    },
-    atan2:func(x,y)
-    {
-        return nasal_call_builtin_cpp_atan2(x,y);
-    },
+    e:     2.7182818284590452354,
+    pi:    3.14159265358979323846264338327950288,
+    sin:   func(x)  {return nasal_call_builtin_sin(x);          },
+    cos:   func(x)  {return nasal_call_builtin_cos(x);          },
+    tan:   func(x)  {return nasal_call_builtin_tan(x);          },
+    exp:   func(x)  {return nasal_call_builtin_exp(x);          }, 
+    ln:    func(x)  {return nasal_call_builtin_cpp_math_ln(x);  },
+    sqrt:  func(x)  {return nasal_call_builtin_cpp_math_sqrt(x);},
+    atan2: func(x,y){return nasal_call_builtin_cpp_atan2(x,y);  }
 };
diff --git a/nasal_builtin.h b/nasal_builtin.h
index 86f6a6e..c6105c4 100644
--- a/nasal_builtin.h
+++ b/nasal_builtin.h
@@ -68,7 +68,7 @@ void builtin_error_occurred(std::string func_name,std::string info)
 }
 
 // register builtin function's name and it's address here in this table below
-// this table must and with {"",NULL}
+// this table must end with {"",NULL}
 struct FUNC_TABLE
 {
     std::string func_name;
@@ -134,10 +134,8 @@ nasal_val* builtin_print(nasal_val* local_scope_addr,nasal_gc& gc)
             case vm_func: std::cout<<"func(...){...}";  break;
         }
     }
-    std::cout<<"\n";
     // generate return value
-    nasal_val* ret_addr=gc.gc_alloc(vm_nil);
-    return ret_addr;
+    return gc.gc_alloc(vm_nil);
 }
 nasal_val* builtin_append(nasal_val* local_scope_addr,nasal_gc& gc)
 {
@@ -157,8 +155,7 @@ nasal_val* builtin_append(nasal_val* local_scope_addr,nasal_gc& gc)
         gc.add_reference(value_address);
         ref_vector.add_elem(value_address);
     }
-    nasal_val* ret_addr=gc.gc_alloc(vm_nil);
-    return ret_addr;
+    return gc.gc_alloc(vm_nil);
 }
 nasal_val* builtin_setsize(nasal_val* local_scope_addr,nasal_gc& gc)
 {
@@ -335,10 +332,13 @@ nasal_val* builtin_split(nasal_val* local_scope_addr,nasal_gc& gc)
             }
         if(check_delimeter)
         {
-            nasal_val* str_addr=gc.gc_alloc(vm_str);
-            str_addr->set_string(tmp);
-            ref_vec.add_elem(str_addr);
-            tmp="";
+            if(tmp.length())
+            {
+                nasal_val* str_addr=gc.gc_alloc(vm_str);
+                str_addr->set_string(tmp);
+                ref_vec.add_elem(str_addr);
+                tmp="";
+            }
             i+=delimeter_len-1;
         }
         else
@@ -763,7 +763,7 @@ nasal_val* builtin_substr(nasal_val* local_scope_addr,nasal_gc& gc)
     std::string str=str_addr->get_string();
     int begin=(int)begin_addr->get_number();
     int len=(int)length_addr->get_number();
-    if(begin+len>=str.length())
+    if(begin+len>str.length())
     {
         builtin_error_occurred("susbtr","index out of range");
         return NULL;