Dashes possible in domain name

index.php

@@ -78,7 +78,7 @@ function show_whois($target) {
   echo "<h2>WHOIS</h2>\n";
   if(preg_match('/^(?!\-)(?:[a-zA-Z\d\-]{0,62}[a-zA-Z\d]\.){1,126}(?!\d+)[a-zA-Z\d]{1,63}$/', $target)) {
     // if domain, skip subdomains
-    preg_match('/[a-zA-Z\d]+\.[a-zA-Z\d]+$/', $target, $m);
+    preg_match('/[a-zA-Z\d\-]+\.[a-zA-Z\d]+$/', $target, $m);
     $target = $m[0];
   }
   $whois = shell_exec("whois " . $target  );