diff --git a/df_check.py b/df_check.py
index 3df01c5..0001b09 100755
--- a/df_check.py
+++ b/df_check.py
@@ -1,9 +1,10 @@
 #!/usr/bin/python2
 
+# import os for statvfs
 import os
 
 
-#fileoperations
+#reading needed files
 file = open("/proc/partitions", "r")
 parts = file.read()
 file.close()
@@ -11,11 +12,10 @@ file = open("/proc/mounts", "r")
 mounts = file.read()
 file.close()
 
-#definitions
 partitions = []
 blocks = []
-
 # getting all local partitions (regardless if mounted or not)
+# and blocks from /proc/partitions and write it to lists
 for line in parts.split("\n"):
     if line and "name" not in line and "sr0" not in line:
         if line.split()[2] != "1":
@@ -29,6 +29,8 @@ blockcount = 0
 counter = 0
 partsnew = []
 blocksnew = []
+# detect disk like /dev/sda itself and
+# filter it from partitions and blocks list
 for part in partitions:
     if hold in part:
         blockcount = blockcount + int(blocks[counter])
@@ -40,11 +42,14 @@ for part in partitions:
         blockcount = 0
     counter += 1
 
+
+# moving back to old var name
+# too lazy to rename everything below
 partitions = partsnew
 blocks = blocksnew
 
 
-#getting mountpoints to devices
+# getting mounted partitions and their mountpoints
 mountpoints = []
 for item in partitions:
     for line in mounts.split("\n"):
@@ -52,31 +57,29 @@ for item in partitions:
             mountpoints.append(line.split()[1])
             break
 
-
-
+# output for debugging
 print "partitions: %s\nblocks: %s\nmountpoints: %s" %(partitions, blocks, mountpoints)
 
-print "\n"
+
 # given paths(mountpoints)
 #path=("/boot", "/", "/dev/sda6")
 path = mountpoints
 
-#output head
 print "mountpoints\tfree megabytes"
 print "------------------------------"
 
-#work path tuple
+# getting usage information and print it to stdout
 for mountpoint in path:
     #check if given path is a mountpoint
-#    if os.path.ismount(mountpoint):
+    if os.path.ismount(mountpoint):
         #create statvfs object
         fs = os.statvfs(mountpoint)
         #calculate free megabytes
         freembytes = fs.f_bavail * fs.f_bsize / 1024**2.0
         #output
         print "%s\t\t%.1f MB" %(mountpoint, freembytes)
-#    else:
-#        print "error: given path is not a mountpoint"
+    else:
+        print "error: given path (%s) is not a mountpoint" %(mountpoint)
 
 
 # end of file