diff --git a/radiorec.py b/radiorec.py
index 97af199..119a650 100755
--- a/radiorec.py
+++ b/radiorec.py
@@ -8,15 +8,45 @@ with "at" or "crontab".
 
 import argparse
 import configparser
+import threading
+import time
 import urllib.request
 
-def main():
-    parser = argparse.ArgumentParser(description='This program records internet radio streams.')
+def _check_args():
+    parser = argparse.ArgumentParser(description='This program records '
+                                              'internet radio streams.')
     parser.add_argument('station', type=str, help='Name of the radio station '
-                                                '(see config file for a list)')
-    parser.add_argument('duration', type=int, help='Recording time in minutes')
-    parser.add_argument('name', nargs='?', type=str, help='A name for the recording')
-    args = parser.parse_args()
+                                               '(see config file for a list)')
+    parser.add_argument('duration', type=_check_duration, 
+                        help='Recording time in minutes')
+    parser.add_argument('name', nargs='?', type=str, 
+                        help='A name for the recording')
+    return parser.parse_args()
+
+def _check_duration(value):
+    try:
+        value = int(value)
+    except ValueError:
+        raise argparse.ArgumentTypeError('Duration must be a positive integer.')
+
+    if value < 1:
+        raise argparse.ArgumentTypeError('Duration must be a positive integer.')
+    else:
+        return value
+
+def record(stoprec):
+    while(not stoprec.is_set()):
+        time.sleep(1)
+
+def main():
+    args = _check_args()
+
+    stoprec = threading.Event()
+    recthread = threading.Thread(target=record, args=(stoprec,))
+    recthread.start()
+    recthread.join(args.duration * 60)
+    if(recthread.is_alive):
+        stoprec.set()
 
 if __name__ == '__main__':
     main()