diff --git a/lights.js b/lights.js
index 3d91db8..c435425 100644
--- a/lights.js
+++ b/lights.js
@@ -56,7 +56,7 @@ export const functions = {
       convert_args: false
     }
   ),
-  constant: new Function(
+  move: new Function(
     (index, arg1, arg2) => { return arg2; },
     {
       requires_arg1: true,
@@ -70,15 +70,8 @@ export const functions = {
       requires_arg2: true,
       convert_args: true
     }),
-  move: new Function(
-    (index, arg1, arg2) => { targets[arg1] = arg2; return arg2; },
-    {
-      requires_arg1: true,
-      requires_arg2: true,
-      convert_args: false
-    }),
   swap: new Function(
-    (index, arg1, arg2) => { let temp = targets[arg1]; targets[arg1] = arg2; return temp; },
+    (index, arg1, arg2) => { let temp = targets[arg2]; targets[arg2] = targets[arg1]; return temp; },
     {
       requires_arg1: true,
       requires_arg2: true,
@@ -109,13 +102,17 @@ function tick_pattern() {
       for (let command of pattern) {
         let name = command.command;
         if (functions[name]) {
-          if (functions[name].options.convert_args) {
+          if (functions[name].options && functions[name].options["convert_args"]) {
             let param_arg1 = parseInt(command.arg1) || targets[command.arg1];
             let param_arg2 = parseInt(command.arg2) || targets[command.arg2];
-            targets[command.arg1] = functions[name].func(i, param_arg1, param_arg2);
+            let result = functions[name].func(i, param_arg1, param_arg2);
+            log.info(`convert ${command.arg1} ${param_arg1} ${command.arg2} ${param_arg2} ${result}`);
+            targets[command.arg1] = result;
           }
           else {
-            targets[command.arg1] = functions[name].func(i, command.arg1, command.arg2);
+            let result = functions[name].func(i, command.arg1, command.arg2);
+            log.info("no convert " +  result);
+            targets[command.arg1] = result;
           }
         }
       }
diff --git a/parse.js b/parse.js
index 5bc4d69..f3df9e0 100644
--- a/parse.js
+++ b/parse.js
@@ -28,6 +28,9 @@ export default function parse(data) {
       ) {
         errors.push(`error parsing line ${lineNumber}, invalid number of args`);
       }
+      else if (!match.options["convert_args"] && parseInt(arg1)) {
+        errors.push(`error parsing line ${lineNumber}, argument ${arg1} cannot be a number`);
+      }
       else {
         parsed.push(
           {