diff --git a/htroot/User_p.html b/htroot/User_p.html
index a424c3d71..50aa1f7cf 100644
--- a/htroot/User_p.html
+++ b/htroot/User_p.html
@@ -97,6 +97,8 @@ User changed: #[username]#
 generic error.
 ::
 Passwords do not match.
+::
+Username too short. Username must be >= 4 Charakters.
 #(/error)#
 <p />
 If you want to manage more Users, return to the <a href="User_p.html?change_user=true&user=#[username]#">user</a> page.
diff --git a/htroot/User_p.java b/htroot/User_p.java
index 64377b382..0074a697e 100644
--- a/htroot/User_p.java
+++ b/htroot/User_p.java
@@ -150,10 +150,15 @@ public class User_p {
                 mem.put(userDB.Entry.DOWNLOAD_RIGHT, downloadRight);
                 mem.put(userDB.Entry.BLOG_RIGHT, blogRight);
 
-                entry=sb.userDB.createEntry(username, mem);
-                sb.userDB.addEntry(entry);
-				prop.put("page_text_username", username);
-				prop.put("page_text", 1);
+                try{
+                    entry=sb.userDB.createEntry(username, mem);
+                    sb.userDB.addEntry(entry);
+                    prop.put("page_text_username", username);
+                    prop.put("page_text", 1);
+                }catch(IllegalArgumentException e){
+                    prop.put("page_error", 3);
+                }
+                
                 
             } else { //edit user
 
diff --git a/source/de/anomic/data/userDB.java b/source/de/anomic/data/userDB.java
index a155af52c..6328a80cb 100644
--- a/source/de/anomic/data/userDB.java
+++ b/source/de/anomic/data/userDB.java
@@ -127,7 +127,7 @@ public final class userDB {
         }
     }    
     
-    public Entry createEntry(String userName, HashMap userProps) {
+    public Entry createEntry(String userName, HashMap userProps) throws IllegalArgumentException{
         Entry entry = new Entry(userName,userProps);
         return entry;
     }
@@ -329,7 +329,7 @@ public final class userDB {
         private String userName;
 		private Calendar oldDate, newDate;
         
-        public Entry(String userName, Map mem) {
+        public Entry(String userName, Map mem) throws IllegalArgumentException {
             if ((userName == null) || (userName.length() == 0)) 
                 throw new IllegalArgumentException("Username needed.");
             if(userName.length()>128){