diff --git a/call.cgi b/call.cgi
index fd9623d..e429e7c 100755
--- a/call.cgi
+++ b/call.cgi
@@ -111,9 +111,8 @@
 
     lines.sort(lambda x,y: cmp(x[6],y[6]))
     for room in ["GRL", "ML1", "ML2", "HSJ"]:
+        wb.remove(wb[room+u"出席表"])
         if room in form:
-            wb.remove(wb.get_sheet_by_name(room+u"出席表"))
-            #.remove()
             ws = wb.create_sheet(title = room+u"出席表")
             extract = [[host, str(student_no),logon[-5:],logoff[-5:], name, reading, dep]
                     for host, logon, logoff, _, _,
@@ -169,6 +168,8 @@
                            showLastColumn=False, showRowStripes=True, showColumnStripes=False)
             tab.tableStyleInfo = style
             ws.add_table(tab)
+        else:
+            wb.remove(wb[room+u"座席表"])
 
     filename="attendancebook"+fr.strftime("%Y%m%d%H%M")+".xlsx"
     tname= tempfile.mktemp(filename)