diff --git a/source/gui/regex.py b/source/gui/regex.py
new file mode 100644
index 0000000..1b505b3
--- /dev/null
+++ b/source/gui/regex.py
@@ -0,0 +1,12 @@
+from math import inf
+
+
+def number(min_length: int = 0, max_length: int = inf) -> str:
+    return r"\d{%s,%s}" % (min_length, max_length if max_length < inf else "")
+
+
+ipv4_check, ipv4_type = r"\d{1,3}(\.\d{1,3}){3}", r"[\d\.]{0,15}"
+port_check, port_type = number(min_length=1, max_length=5), number(min_length=0, max_length=5)
+
+username_check, username_type = r".{1,16}", r".{0,16}"
+
diff --git a/source/gui/scene/RoomCreate.py b/source/gui/scene/RoomCreate.py
index 70997b6..c7db5af 100644
--- a/source/gui/scene/RoomCreate.py
+++ b/source/gui/scene/RoomCreate.py
@@ -1,6 +1,6 @@
 from typing import TYPE_CHECKING
 
-from source.gui import widget, texture
+from source.gui import widget, texture, regex
 from source.gui.scene import RoomHost
 from source.gui.scene.abc import Scene
 from source.network.packet import PacketSettings
@@ -44,8 +44,8 @@ class RoomCreate(Scene):
 
             style=texture.Input.Style1,
 
-            type_regex=r"\d{0,5}",
-            check_regex=r"\d{1,5}",
+            type_regex=regex.port_type,
+            check_regex=regex.port_check,
 
             label_text="52321"
         )
@@ -67,7 +67,8 @@ class RoomCreate(Scene):
 
             x=0.2, y=0.45, width=0.15, height=0.1,
 
-            type_regex=r".{0,16}",
+            type_regex=regex.username_type,
+            check_regex=regex.username_check,
 
             style=texture.Input.Style1,
 
@@ -89,8 +90,8 @@ class RoomCreate(Scene):
 
             x=0.2, y=0.86, width=0.1, height=0.08,
 
-            type_regex=r"\d{0,4}",
-            check_regex=r"\d+",
+            type_regex=regex.number(min_length=0, max_length=4),
+            check_regex=regex.number(min_length=1, max_length=4),
 
             style=texture.Input.Style1,
 
@@ -110,8 +111,8 @@ class RoomCreate(Scene):
 
             x=0.2, y=0.76, width=0.1, height=0.08,
 
-            type_regex=r"\d{0,4}",
-            check_regex=r"\d+",
+            type_regex=regex.number(min_length=0, max_length=4),
+            check_regex=regex.number(min_length=1, max_length=4),
 
             style=texture.Input.Style1,
 
@@ -201,8 +202,8 @@ class RoomCreate(Scene):
 
             x=0.7, y=0.68, width=0.2, height=0.08,
 
-            type_regex=r"\d{0,4}",
-            check_regex=r"\d+",
+            type_regex=regex.number(min_length=0, max_length=4),
+            check_regex=regex.number(min_length=1, max_length=4),
 
             style=texture.Input.Style1,
 
diff --git a/source/gui/scene/RoomJoin.py b/source/gui/scene/RoomJoin.py
index c0d8f25..59fe14a 100644
--- a/source/gui/scene/RoomJoin.py
+++ b/source/gui/scene/RoomJoin.py
@@ -2,7 +2,7 @@ from typing import TYPE_CHECKING, Optional
 
 from source import network
 from source.gui.scene.abc import Scene
-from source.gui import widget, texture
+from source.gui import widget, texture, regex
 
 if TYPE_CHECKING:
     from source.gui.window import Window
@@ -29,7 +29,8 @@ class RoomJoin(Scene):
             widget.Input,
             x=0.4, y=0.55, width=0.2, height=0.1,
 
-            type_regex=r".{0,16}",
+            type_regex=regex.username_type,
+            check_regex=regex.username_check,
 
             style=texture.Input.Style1,
 
@@ -42,8 +43,8 @@ class RoomJoin(Scene):
             widget.Input,
             x=0.4, y=0.45, width=0.13, height=0.1,
 
-            type_regex=r"[\d\.]{0,15}",
-            check_regex=r"\d{1,3}(\.\d{1,3}){3}",
+            type_regex=regex.ipv4_type,
+            check_regex=regex.ipv4_check,
 
             style=texture.Input.Style1,
 
@@ -54,8 +55,8 @@ class RoomJoin(Scene):
             widget.Input,
             x=0.53, y=0.45, width=0.07, height=0.1,
 
-            type_regex=r"\d{0,5}",
-            check_regex=r"\d{1,5}",
+            type_regex=regex.port_type,
+            check_regex=regex.port_check,
 
             label_text="52321",