diff --git a/prototypes/idb2rwtxn.html b/prototypes/idb2rwtxn.html
index 061990a0..c53d553e 100644
--- a/prototypes/idb2rwtxn.html
+++ b/prototypes/idb2rwtxn.html
@@ -4,8 +4,8 @@
 	<meta charset="utf-8">
 </head>
 <body>
-    <button id="doit">Do It!</button>
-	<script type="module">
+    <button id="doit">Do It 3!</button>
+	<script type="text/javascript">
 		function reqAsPromise(req) {
 			return new Promise((resolve, reject) => {
 				req.addEventListener("success", event => resolve(event.target.result));
@@ -21,54 +21,58 @@
 		}
 
 		async function main() {
-			let isNew = false;
-			const openReq = window.indexedDB.open("two-read-write-txn", 1);
-			openReq.onupgradeneeded = (ev) => {
-				const db = ev.target.result;
-				const store = db.createObjectStore("test", {keyPath: "id"});
-                store.add({id: 6});
-			};
-			const db = await reqAsPromise(openReq);
-			
-            console.log("open txn1");
-            const txn1 = db.transaction("test", "readwrite");
-            
-            const test1 = txn1.objectStore("test");
-            console.log("request value1");
-            const value1 = await reqAsPromise(test1.get(6));
-            console.log("value1", value1);
-            value1.previous = 5;
-            value1.next = null;
+            try  {
 
-            let txn2, test2, prom2, value2;
+                const openReq = window.indexedDB.open("two-read-write-txn", 1);
+                openReq.onupgradeneeded = (ev) => {
+                    const db = ev.target.result;
+                    const store = db.createObjectStore("test", {keyPath: "id"});
+                    store.add({id: 6});
+                };
+                const db = await reqAsPromise(openReq);
+                
+                console.log("open txn1");
+                const txn1 = db.transaction("test", "readwrite");
+                
+                const test1 = txn1.objectStore("test");
+                console.log("request value1");
+                const value1 = await reqAsPromise(test1.get(6));
+                console.log("value1", value1);
+                value1.previous = 5;
+                value1.next = null;
 
-            // prevent deadlock
-            (async function() {
-                console.log("open txn2");
-                txn2 = db.transaction("test", "readwrite");
-                test2 = txn2.objectStore("test");
-                console.log("request value2");
-                prom2 = reqAsPromise(test2.get(6));
-                value2 = await prom2;
-                console.log("read value2");
-            })();
-            
-            console.log("write value1");
-            test1.put(value1);
-            await txnAsPromise(txn1);
+                let txn2, test2, prom2, value2;
 
-            await prom2;
-            console.log("value2", value2);            
-            value2.next = 7;
-            console.log("write value2");
-            test2.put(value2);
-            await txnAsPromise(txn2);
+                // prevent deadlock
+                (async function() {
+                    console.log("open txn2");
+                    txn2 = db.transaction("test", "readwrite");
+                    test2 = txn2.objectStore("test");
+                    console.log("request value2");
+                    prom2 = reqAsPromise(test2.get(6));
+                    value2 = await prom2;
+                    console.log("read value2");
+                })();
+                
+                console.log("write value1");
+                test1.put(value1);
+                await txnAsPromise(txn1);
 
-            const txn3 = db.transaction("test", "readonly");
-            const value3 = await reqAsPromise(txn3.objectStore("test").get(6));
+                await prom2;
+                console.log("value2", value2);            
+                value2.next = 7;
+                console.log("write value2");
+                test2.put(value2);
+                await txnAsPromise(txn2);
 
-            alert("done " + JSON.stringify(value3));
+                const txn3 = db.transaction("test", "readonly");
+                const value3 = await reqAsPromise(txn3.objectStore("test").get(6));
 
+                alert("done " + JSON.stringify(value3));
+
+            } catch (err) {
+                alert(`error ${err.message} ${err.name} ${err.stack}`);
+            }
 		}
         document.getElementById("doit").addEventListener("click", main);
 	</script>
