diff --git a/addon/www/index.cgi b/addon/www/index.cgi
index 46b5811..2802d8f 100644
--- a/addon/www/index.cgi
+++ b/addon/www/index.cgi
@@ -1,36 +1,12 @@
 #!/bin/tclsh
 
-load tclrega.so
+source /usr/local/addons/rmupdate/lib/querystring.tcl
+source /usr/local/addons/rmupdate/lib/session.tcl
 
-catch {
-  set input $env(QUERY_STRING)
-  set pairs [split $input &]
-  foreach pair $pairs {
-    if {0 != [regexp "^(\[^=]*)=(.*)$" $pair dummy varname val]} {
-      set $varname $val
-    }
-  }
-}
-
-if {[info exists sid] > 0} {
-    # Session prüfen
-    if {
-        ([string index $sid 0] != "@")
-        || ([string index $sid [expr [string length $sid] -1]]  != "@")
-        || ([string length $sid] != 12)} {
-        puts {error: session invalid}
-    } else {
-        regsub -all {@} $sid "" sid
-        set res [lindex [rega_script "Write(system.GetSessionVarStr('$sid'));"] 1]
-        if {$res != ""} {
-            # gültige Session
-            set fp [open "/usr/local/addons/rmupdate/www/rmupdate.html" r]
+if {[info exists sid] && [check_session $sid]} {
+set fp [open "/usr/local/addons/rmupdate/www/rmupdate.html" r]
             puts -nonewline [read $fp]
             close $fp
-        } else {
-            puts {error: session invalid}
-        }
-    }
 } else {
-    puts {error: no session}
+    puts {error: invalid session}
 }