Added status if the video is in the database and fixed some errors.

ContentScript.js

@@ -9,10 +9,16 @@ chrome.runtime.onMessage.addListener( // Detect URL Changes
         SponsorsLookup(request.id);
     }
 
-    //message from popup script
+    //messages from popup script
     if (request.message === 'sponsorStart') {
       sponsorMessageStarted();
     }
+
+    if (request.message === 'infoFound') {
+      sendResponse({
+        found: true
+      })
+    }
 });
 
 function SponsorsLookup(id) {

popup.html

@@ -7,6 +7,14 @@
     <div class="main">
       <center>
         <h1>SponsorBlock</h1>
+
+        <!-- If the video was found in the database -->
+        <div id="videoFound">
+  
+        </div>
+
+        <br/>
+
         <div>
           <button id="sponsorStart">Sponsorship Starts</button>
         </div>

popup.js

@@ -8,10 +8,10 @@ var startTimeChosen = false;
 var videoTimes = [];
 //load video times
 chrome.storage.local.get(['videoTimes'], function(result) {
-  if (result.videoTimes != undefined) {
+  if (result.videoTimes != undefined && result.videoTimes != []) {
     videoTimes = result.videoTimes;
 
-    if (videoTimes[videoTimes.length - 1].length < 2) {
+    if (videoTimes[videoTimes.length - 1]!= undefined && videoTimes[videoTimes.length - 1].length < 2) {
       startTimeChosen = true;
     }
 
@@ -19,16 +19,35 @@ chrome.storage.local.get(['videoTimes'], function(result) {
   }
 });
 
+//check if this video's sponsors are known
+chrome.tabs.query({
+  active: true,
+  currentWindow: true
+}, tabs => {
+  chrome.tabs.sendMessage(
+    tabs[0].id,
+    {from: 'popup', message: 'infoFound'},
+    infoFound
+  );
+})
+
+function infoFound(request) {
+  if (request.found) {
+    document.getElementById("videoFound").innerHTML = "This video's sponsors are in the database!"
+  } else {
+    document.getElementById("videoFound").innerHTML = "No sponsors found"
+  }
+}
+
 function sendSponsorStartMessage() {
     //the content script will get the message if a YouTube page is open
     chrome.tabs.query({
       active: true,
       currentWindow: true
     }, tabs => {
-      // ...and send a request for the DOM info...
       chrome.tabs.sendMessage(
         tabs[0].id,
-        {from: 'popup', subject: 'DOMInfo', message: 'sponsorStart'}
+        {from: 'popup', message: 'sponsorStart'}
       );
     });
 }