diff --git a/README.md b/README.md
index f661de9..f0ee820 100644
--- a/README.md
+++ b/README.md
@@ -100,3 +100,4 @@ export def cmat {
   - [ ] Figure out reusing functions across exported functions
   - [x] Comments
   - [ ] Anonyms functions
+  - [ ] Label keyword
\ No newline at end of file
diff --git a/bin/keyboard.dm42 b/bin/keyboard.dm42
index b594957..9a9651d 100644
--- a/bin/keyboard.dm42
+++ b/bin/keyboard.dm42
@@ -1,12 +1,26 @@
-// Lets you use your calculator to compose scores of utmost beauty.
-
+// Lets you use your calculator to compose scores of utmost elegance.
 export def key {
-    GETKEY
+    GETKEY1
     STO 00
-    if { } >= { 10 } {
+
+    // Exit if key 33 is pressed (EXIT)
+    if { DUP } == { 33 } {
+        DROP
+        STOP
+    }
+
+    // Play tone 0 if key 10 is pressed (SIN)
+    if { DUP } == { 10 } {
+        DROP
         TONE 0
         GTO key
     }
+
+    // Do nothing if other keys are pressed
+    if { } > { 10 } {
+        GTO key
+    }
+
     TONE IND 00
     GTO key
 }
diff --git a/src/tokenize.rs b/src/tokenize.rs
index d906fda..96b0fbe 100644
--- a/src/tokenize.rs
+++ b/src/tokenize.rs
@@ -48,7 +48,7 @@ impl Tokenizer {
 
         // Comments
         if self.idx + 2 < self.chars.len() && &self.chars[self.idx..self.idx + 2] == &['/', '/'] {
-            while self.chars[self.idx] != '\n' {
+            while self.idx < self.chars.len() && self.chars[self.idx] != '\n' {
                 self.idx += 1;
             }
             self.skip_whitespace();