diff --git a/assets/jscon.js b/assets/jscon.js
index 2b19468..594b9e2 100644
--- a/assets/jscon.js
+++ b/assets/jscon.js
@@ -1,8 +1,14 @@
-function readConsoleInput() {
+println("JS Console");
+var cmdHistory = []; // zeroth element is the oldest
+var cmdHistoryScroll = 0; // 0 for outside-of-buffer, 1 for most recent
+while (true) {
+    print("JS> ");
+
     var cmdbuf = "";
-    var key = -1;
-    while (key != 10 && key != 13) {
-        key = vm.readKey();
+
+    while (true) {
+        var key = vm.readKey();
+
         // printable chars
         if (key >= 32 && key <= 126) {
             var s = String.fromCharCode(key);
@@ -10,35 +16,54 @@ function readConsoleInput() {
             print(s);
         }
         // backspace
-        else if (key == 8 && cmdbuf.length > 0) {
+        else if (key === 8 && cmdbuf.length > 0) {
             cmdbuf = cmdbuf.substring(0, cmdbuf.length - 1);
             print(String.fromCharCode(key));
         }
-        // up down key
-        else if (key >= 19 && key <= 20) {
-            return key;
-        }
-        // left right key
-        else if (key >= 19 && key <= 20) {
-            //
-        }
-    }
-    return cmdbuf;
-}
+        // enter
+        else if (key === 10 || key === 13) {
+            println();
+            try {
+                println(eval(cmdbuf));
+            }
+            catch (e) {
+                println(e);
+            }
+            finally {
+                if (cmdbuf.trim().length > 0)
+                    cmdHistory.push(cmdbuf);
 
-println("JS Console");
-while (true) {
-    print("JS> ");
-
-    var cmdbuf = readConsoleInput();
-
-    if (typeof cmdbuf == "string") {
-        println();
-        try {
-            println(eval(cmdbuf));
+                cmdHistoryScroll = 0;
+                break;
+            }
         }
-        catch (e) {
-            println(e);
+        // up arrow
+        else if (key === 19 && cmdHistory.length > 0 && cmdHistoryScroll < cmdHistory.length) {
+            cmdHistoryScroll += 1;
+
+            // back the cursor in order to type new cmd
+            for (xx = 0; xx < cmdbuf.length; xx++) print(String.fromCharCode(8));
+            cmdbuf = cmdHistory[cmdHistory.length - cmdHistoryScroll];
+            // re-type the new command
+            print(cmdbuf);
+
+        }
+        // down arrow
+        else if (key === 20) {
+            if (cmdHistoryScroll > 0) {
+                // back the cursor in order to type new cmd
+                for (xx = 0; xx < cmdbuf.length; xx++) print(String.fromCharCode(8));
+                cmdbuf = cmdHistory[cmdHistory.length - cmdHistoryScroll];
+                // re-type the new command
+                print(cmdbuf);
+
+                cmdHistoryScroll -= 1;
+            }
+            else {
+                // back the cursor in order to type new cmd
+                for (xx = 0; xx < cmdbuf.length; xx++) print(String.fromCharCode(8));
+                cmdbuf = "";
+            }
         }
     }
 }
\ No newline at end of file