diff --git a/scripts/content.js b/scripts/content.js
index 03234d1..b3a76bd 100644
--- a/scripts/content.js
+++ b/scripts/content.js
@@ -3,7 +3,7 @@
         // console.log(request);
         switch (request.from) {
             case "DataExtracter:Extract":
-                let data = extractData(request.itemsSelector, request.fieldSelectors);
+                let data = extractTabData(request.itemsSelector, request.fieldSelectors);
                 if (sendResponse) sendResponse(data);
                 break;
             case "DataExtracter:GotoUrl":
@@ -22,7 +22,7 @@
     }
 );
 
-function extractData(itemsSelector, fieldSelectors) {
+function extractTabData(itemsSelector, fieldSelectors) {
     return $(itemsSelector).toArray().map(
         item => fieldSelectors.map(
             selector => {
@@ -69,7 +69,9 @@ extract('.list-item', ['a.title', 'a.title@href'])
         return;
     }
     if (args.length == 2) {
-        saveFileAsk(extractData(args[0], args[1]));
+        let data = extractTabData(args[0], args[1]);
+        data.unshift(args[1]);
+        saveFileAsk(data);
         return;
     }
     let message = {
diff --git a/scripts/extract.js b/scripts/extract.js
index 6f8918d..2271d27 100644
--- a/scripts/extract.js
+++ b/scripts/extract.js
@@ -4,21 +4,36 @@
  * @param {Array<string>} fieldSelectors fields selectors for selecting fields (data columns) under each item
  * @param {...any} args url list / url templates, page numers, either [from, to, interval] or [...pages]
  */
-function extract(itemsSelector, fieldSelectors, ...args) {
+async function extract(itemsSelector, fieldSelectors, ...args) {
+    let data = await extractData(itemsSelector, fieldSelectors, ...args);
+    data.unshift(fieldSelectors);
+    saveFileAsk(data);
+    resolve("save done.")
+}
+
+/**
+ * Extract data from current tab / multiple urls.
+ * @param {string} itemsSelector items selectors for selecting items (data rows)
+ * @param {Array<string>} fieldSelectors fields selectors for selecting fields (data columns) under each item
+ * @param {...any} args url list / url templates, page numers, either [from, to, interval] or [...pages]
+ */
+async function extractData(itemsSelector, fieldSelectors, ...args) {
     let urls = [];
-    let listOrTempl = args.shift();
-    if (listOrTempl instanceof Array) {
-        urls = listOrTempl;
-    } else if (url) {
-        let urlTempl = listOrTempl;
-        if (args[0] instanceof Array) {
-            urls = args[0].map(p => urlTempl.replace("${page}", p));
-        } else if (args.length >= 3) {
-            let from = args.shift();
-            let to = args.shift();
-            let interval = args.shift();
-            for (let i = from; i <= to; i += interval) {
-                urls.push(urlTempl.replace("${page}", i));
+    let arg = args.shift();
+    if (arg instanceof Array) {
+        urls = arg;
+    } else {
+        let urlTempl = arg;
+        if (urlTempl) {
+            if (args[0] instanceof Array) {
+                urls = args[0].map(p => urlTempl.replace("${page}", p));
+            } else if (args.length >= 3) {
+                let from = args.shift();
+                let to = args.shift();
+                let interval = args.shift();
+                for (let i = from; i <= to; i += interval) {
+                    urls.push(urlTempl.replace("${page}", i));
+                }
             }
         }
     }
@@ -35,20 +50,18 @@ function extract(itemsSelector, fieldSelectors, ...args) {
                     results => {
                         data.push(...results);
                         return redirectTab(tab, url).then(
-                            () => extractData(tab, itemsSelector, fieldSelectors)
+                            () => extractTabData(tab, itemsSelector, fieldSelectors)
                         );
                     },
                     () => p
                 ), Promise.resolve([]));
             } else {
-                pms = extractData(tab, itemsSelector, fieldSelectors);
+                pms = extractTabData(tab, itemsSelector, fieldSelectors);
             }
             pms.then(
                 results => {
                     data.push(...results);
-                    data.unshift(fieldSelectors);
-                    saveFileAsk(data);
-                    resolve("save done.")
+                    resolve(data);
                 },
                 err => reject(err)
             );
@@ -74,13 +87,13 @@ function redirectTab(tab, url) {
 }
 
 /**
- * extract data in from the target tab, usually used to detect if the content script is ready.
+ * extract data in from the target tab.
  * @param {any} tab target tab
  * @param {string} itemsSelector items selectors for selecting items (data rows)
  * @param {Array<string>} fieldSelectors fields selectors for selecting fields (data columns) under each item
  * @returns {Promise<string[]>} a promise of extracted data
  */
-function extractData(tab, itemsSelector, fieldSelectors) {
+function extractTabData(tab, itemsSelector, fieldSelectors) {
     let req = {
         from: "DataExtracter:Extract",
         itemsSelector: itemsSelector,