diff --git a/ajax.php b/ajax.php
index ddf87d6..c7b47fa 100644
--- a/ajax.php
+++ b/ajax.php
@@ -32,7 +32,7 @@ if ($_GET['section'] == "localTx") {
             $listElem[3] = getName($listElem[2]);
             if ($listElem[2] !== "??????????") {
                if (!is_numeric($listElem[2])) {
-                  if (constant("SHOWQRZ")) {
+                  if (defined("SHOWQRZ")) {
                      $listElem[2] = "<a target=\"_new\" href=\"https://qrz.com/db/$listElem[2]\">".str_replace("0","&Oslash;",$listElem[2])."</a>";
                   } else {
                      $listElem[2] = "<a target=\"_new\" href=\"http://dmr.darc.de/dmr-userreg.php?callsign=$listElem[2]\">".$listElem[2]."</a>";
@@ -47,7 +47,7 @@ if ($_GET['section'] == "localTx") {
          if ($listElem[5] == "RF" && ($listElem[1]=="D-Star" || startsWith($listElem[1], "DMR") || $listElem[1]=="YSF" || $listElem[1]=="P25")) {
             if ($listElem[2] !== "??????????") {
                if (!is_numeric($listElem[2])) {
-                  if (constant("SHOWQRZ")) {
+                  if (defined("SHOWQRZ")) {
                      $listElem[2] = "<a target=\"_new\" href=\"https://qrz.com/db/$listElem[2]\">".str_replace("0","&Oslash;",$listElem[2])."</a>";
                   } else {
                      $listElem[2] = "<a target=\"_new\" href=\"http://dmr.darc.de/dmr-userreg.php?callsign=$listElem[2]\">".$listElem[2]."</a>";
diff --git a/include/functions.php b/include/functions.php
index 38feb31..07e0606 100644
--- a/include/functions.php
+++ b/include/functions.php
@@ -25,8 +25,11 @@ function getMMDVMHostFileVersion() {
 function getFirmwareVersion() {
    $logPath = MMDVMLOGPATH."/".MMDVMLOGPREFIX."-".date("Y-m-d").".log";
    $logLines = explode("\n", `grep "MMDVM protocol version" $logPath`);
-   $firmware = substr($logLines[count($logLines)-2], strpos($logLines[count($logLines)-2], "description")+13, strlen($logLines[count($logLines)-2])-strpos($logLines[count($logLines)-2], "description")+13);
-   if (strlen($firmware) > 0) {
+   $firmware = "n/a";
+   if (count($logLines) >= 2) {
+      $firmware = substr($logLines[count($logLines)-2], strpos($logLines[count($logLines)-2], "description")+13, strlen($logLines[count($logLines)-2])-strpos($logLines[count($logLines)-2], "description")+13);
+   }
+   if ($firmware != "n/a") {
       $fp = fopen('/tmp/MMDVMFirmware.txt', 'w');
       fwrite($fp, $firmware);
       fclose($fp);
@@ -45,26 +48,26 @@ function setDMRNetwork($network) {
 }
 
 function getDMRNetwork() {
-   if (file_exists('config/DMRNetwork.txt')) {
-      $fp = fopen('config/DMRNetwork.txt', 'r');
-      $network = fread($fp, filesize("config/DMRNetwork.txt"));
+   $filename = 'config/DMRNetwork.txt';
+   $network = '';
+   if (file_exists($filename)) {
+      $fp = fopen($filename, 'r');
+      $network = fread($fp, filesize($filename));
       fclose($fp);
-      return $network;	 
-   } else {
-   	  return "";
    }
-   
+   return $network;
 }
 
 function getDMRNetwork2() {
-   if (file_exists('../config/DMRNetwork.txt')) {
-   	  $fp = fopen('../config/DMRNetwork.txt', 'r');
-      $network = fread($fp, filesize("../config/DMRNetwork.txt"));
+   $filename = '../config/DMRNetwork.txt';
+   $network = '';
+   if (file_exists($filename)) {
+      $fp = fopen($filename, 'r');
+      $network = fread($fp, filesize($filename));
       fclose($fp);
-      return $network;	 
-   } else {
-   	  return "";
    }
+   return $network;
+
 }
 
 function getDMRMasterState() {
@@ -445,7 +448,7 @@ function getLastHeard($logLines, $onlyLast) {
             }
             if ($listElem[2] !== "??????????") {
                if (!is_numeric($listElem[2])) {
-                  if (constant("SHOWQRZ")) {
+                  if (defined("SHOWQRZ")) {
                      $listElem[2] = "<a target=\"_new\" href=\"https://qrz.com/db/$listElem[2]\">".str_replace("0","&Oslash;",$listElem[2])."</a>";
                   } else {
                      $listElem[2] = "<a target=\"_new\" href=\"http://dmr.darc.de/dmr-userreg.php?callsign=$listElem[2]\">".$listElem[2]."</a>";
diff --git a/include/lh.php b/include/lh.php
index 6e50b4c..1574dee 100644
--- a/include/lh.php
+++ b/include/lh.php
@@ -36,7 +36,7 @@ for ($i = 0;  ($i < $totalLH); $i++) {
       echo"<td nowrap>$listElem[1]</td>";
       if ($listElem[2] !== "??????????") {
          if (!is_numeric($listElem[2])) {
-            if (constant("SHOWQRZ")) {
+            if (defined("SHOWQRZ")) {
                echo"<td nowrap><a target=\"_new\" href=\"https://qrz.com/db/$listElem[2]\">".str_replace("0","&Oslash;",$listElem[2])."</a></td>";
             } else {
                echo"<td nowrap><a target=\"_new\" href=\"http://dmr.darc.de/dmr-userreg.php?callsign=$listElem[2]\">".$listElem[2]."</td>";
diff --git a/include/localtx.php b/include/localtx.php
index 3913dd6..16e8aa2 100644
--- a/include/localtx.php
+++ b/include/localtx.php
@@ -41,7 +41,7 @@ for ($i = 0; $i < count($localTXList); $i++) {
       echo"<td nowrap>$listElem[1]</td>";
       if ($listElem[2] !== "??????????") {
          if (!is_numeric($listElem[2])) {
-            if (constant("SHOWQRZ")) {
+            if (defined("SHOWQRZ")) {
                echo"<td nowrap><a target=\"_new\" href=\"https://qrz.com/db/$listElem[2]\">".str_replace("0","&Oslash;",$listElem[2])."</a></td>";
             } else {
                echo"<td nowrap><a target=\"_new\" href=\"http://dmr.darc.de/dmr-userreg.php?callsign=$listElem[2]\">".$listElem[2]."</td>";
diff --git a/txinfo.php b/txinfo.php
index 372cde6..290ff00 100644
--- a/txinfo.php
+++ b/txinfo.php
@@ -27,7 +27,7 @@ foreach ($lastHeard as $listElem) {
       echo"<td nowrap>$listElem[1]</td>";
       /*if ($listElem[2] !== "??????????") {
          if (!is_numeric($listElem[2])) {
-            if (constant("SHOWQRZ")) {
+            if (defined("SHOWQRZ")) {
                echo"<td nowrap><a target=\"_new\" href=\"https://qrz.com/db/$listElem[2]\">".str_replace("0","&Oslash;",$listElem[2])."</a></td>";
             } else {
                echo"<td nowrap><a target=\"_new\" href=\"http://dmr.darc.de/dmr-userreg.php?callsign=$listElem[2]\">".$listElem[2]."</td>";