function OpenManager() {
  chrome.tabs.create({url:"manager.html"})
}
document.getElementById("managerBtn").onclick = OpenManager
chrome.tabs.getSelected(function(tab){
  document.getElementById("newEntryTitle").value = tab.title
})
document.getElementById("newEntryUrl").value = document.URL

@@ -223,19 +223,18 @@
 b.title%0A
-%7D)%0A
+  
 document
@@ -276,17 +276,15 @@
 e = 
-document.URL
+tab.url%0A%7D)
 %0A

Set entry url correctly