diff --git a/bwifi.sh b/bwifi.sh
index aaa3ba8..00d2329 100755
--- a/bwifi.sh
+++ b/bwifi.sh
@@ -1,16 +1,21 @@
 #!/usr/bin/env bash
 
+# Change the following variable to your username and password for school network authorization.
 username=1970111222
 password=123123321
 
-# get authorizing location from 302 response header
-# use an IP address to bypass the DNS lookup
+# Get authorizing location from 302 response header.
+# Since sometimes the school network don't hijack DNS lookup query, and it may take such a long time
+# during DNS lookup. So we use an IP address to bypass the DNS lookup. Any fixed IP address providing
+# HTTP service can take place of the "119.29.29.29".
 echo 'sending a http request...'
 res_headers=$(curl --request GET --head --no-progress-meter http://119.29.29.29/)
 echo 'response received'
 
+# If authorizing is requested, school network will respond any HTTP (not HTTPS) request with an 302
+# response and its "Server" field is "DrcomServer"
 if ! grep "Server: DrcomServer" <<< $res_headers ; then
-    echo "didn't receive a response from DrcomServer, you may be online now."
+    echo "didn't receive a response from DrcomServer, you may already be online."
     exit 1
 fi