diff --git a/GUI.py b/GUI.py
index 097f2f5..859e8b2 100644
--- a/GUI.py
+++ b/GUI.py
@@ -2,6 +2,9 @@
 # -*- coding: utf-8 -*-
 """
 GUI
+
+bug:
+    stuID未能显示；没有对输入情况进行判断。
 """
 import tkinter as tk
 import tkinter.messagebox
@@ -200,8 +203,3 @@ def outputAs_all():
                             command=outputAs_all).place(x=30, y=300)
 
 window.mainloop()
-
-'''
-bug:
-    stuID未能显示
-'''
diff --git a/__init__.py b/__init__.py
index 3cc5de0..1ebd81f 100644
--- a/__init__.py
+++ b/__init__.py
@@ -8,7 +8,7 @@
 Pull Requests & issues welcome!
 
 @Author: MiaoTony, ZegWe, Cooook, Pinyi Qian
-@UpdateLog: Please refer to `CHANGELOG.md`.
+@ChangeLog: Please refer to `CHANGELOG.md`.
 
 """
 
diff --git a/generateICS.py b/generateICS.py
index 5739f5d..3965c8d 100644
--- a/generateICS.py
+++ b/generateICS.py
@@ -92,8 +92,7 @@ def create_ics(lessons, semester_start_date):
             try:
                 event.add('description', lesson.output_description(week=week))
             except UnicodeDecodeError:
-                print("ERROR!")
-                exit(6)  # 放弃python2.x了
+                raise Exception("ERROR!")  # 放弃python2.x了
             cal.add_component(event)
     return cal
 
@@ -136,7 +135,7 @@ def export_ics(cal, semester_year, semester, stuID):
             tem_path = os.path.abspath(tem.name)
             tem.write(cal.to_ical())
             tem_filename = tem.name
-            tem.read()  # fix a py2.7 bug... issue#2
+            tem.read()  # fix a py2.7 bug...
             tem.close()
             # print(getsizeof(tem.read()))
             is_update = not is_same(tem_path, filename)
diff --git a/generateXLSX.py b/generateXLSX.py
index 93c7801..c94dd86 100644
--- a/generateXLSX.py
+++ b/generateXLSX.py
@@ -34,13 +34,13 @@ def create_xls(lessons, semester_year, semester, stuID):
     sheet.column_dimensions['A'].width = 3
     sheet.row_dimensions[1].height = 20
     sheet.row_dimensions[2].height = 20
-    # print('1\n')
+
     for i in range(1, 12):
         sheet.cell(i + 2, 1, i).alignment = alignment
         sheet.row_dimensions[i + 2].height = 60
     weekday = ['一', '二', '三', '四', '五', '六', '天']
     ab = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I']
-    # print('2\n')
+
     for i in range(0, 7):
         sheet.cell(2, i + 2, '星期' + weekday[i]).alignment = alignment
         sheet.column_dimensions[ab[i + 1]].width = 20
diff --git a/getClassSchedule.py b/getClassSchedule.py
index 454f09d..a21390e 100644
--- a/getClassSchedule.py
+++ b/getClassSchedule.py
@@ -81,29 +81,28 @@ def aao_login(stuID, stuPwd, captcha_str, retry_cnt=1):
                 logging.debug(r2.text)
                 temp_key = temp_token_match.search(r2.text)
                 if temp_key:  # 找到密钥说明没有登录成功，需要重试
-                    print("ID, Password or Captcha ERROR! Login ERROR!\n")
+                    # print("ID, Password or Captcha ERROR! Login ERROR!\n")
                     temp_key = temp_key.group(1)
                     logging.debug(temp_key)
-                    exit(2)
+                    raise Exception("ID, Password or Captcha ERROR! Login ERROR!")
                 elif re.search(r"ui-state-error", r2.text):  # 过快点击
                     print("ERROR! 请不要过快点击!\n")
                     time.sleep(1)
                     try_cnt += 1
                     # session.headers["User-Agent"] = UAs[1]  # random.randint(0, len(UAs)-1)  # 换UA也不行
-                    # exit(3)
                 else:
                     temp_soup = BeautifulSoup(r2.text.encode('utf-8'), 'lxml')
                     name = temp_soup.find('a', class_='personal-name').string.strip()
                     print("Login OK!\nHello, {}!".format(name))
                     return name
             else:
-                print("Login ERROR!\n")
-                exit(1)
+                # print("Login ERROR!\n")
+                raise Exception("Login ERROR!")
         else:
-            print('Search token ERROR!\n')
-            exit(1)
-    print("ERROR! 过一会儿再试试吧...\n")
-    exit(3)
+            # print('Search token ERROR!\n')
+            raise Exception("Search token ERROR!")
+    # print("ERROR! 过一会儿再试试吧...\n")
+    raise Exception("ERROR! 过一会儿再试试吧...")
 
 
 def getCourseTable(choice=0):
@@ -154,8 +153,8 @@ def getCourseTable(choice=0):
         # logging.debug(session.cookies.get_dict())
         return courseTable
     else:
-        print("Get ids ERROR!")
-        exit(4)
+        # print("Get ids ERROR!")
+        raise Exception("Get ids ERROR!")
 
 
 def parseCourseTable(courseTable):
diff --git a/main.py b/main.py
index b54fd95..20f94a3 100644
--- a/main.py
+++ b/main.py
@@ -80,7 +80,7 @@
             # stuPwd = input('Please input your password:')
             stuPwd = getpass('Please input your password:(不会回显，输入完成<ENTER>即可)')
 
-        # Captcha 验证码 # Fix Issue #13 bug, but only for Windows & MacOS.
+        # Captcha 验证码 # Fix Issue #13 bug.
         captcha_resp = session.get(host + '/eams/captcha/image.action')  # Captcha 验证码图片
         img_path = os.path.join(os.getcwd(), 'captcha.jpg')
         with open(img_path, 'wb') as captcha_fp:
@@ -95,6 +95,7 @@
                 os.startfile(img_path)
         except:
             from PIL import Image
+
             # captcha_img = Image.open(BytesIO(captcha_resp.content))
             captcha_img = Image.open(img_path)
             captcha_img.show()  # show the captcha
@@ -138,7 +139,7 @@
         print("Thanks for your use! 欢迎来GitHub上点个Star呢！")
 
     except Exception as e:
-        print("ERROR! 欢迎在GitHub上提出issue & Pull Request!")
+        print("ERROR! 如果遇到技术问题，欢迎在GitHub上提出issue & Pull Request!")
         print(e)
     finally:
         session.cookies.clear()  # 清一下cookie
diff --git a/settings.py b/settings.py
index 612198e..4a280d6 100644
--- a/settings.py
+++ b/settings.py
@@ -8,4 +8,4 @@
 
 DEBUG = False
 
-VERSION = "V0.15.1.20200520"
+VERSION = "V0.15.2.20200520"