fix multiplayer mode

diff --git a/res/micropolis.tcl b/res/micropolis.tcl
index 954688483b74316c274a0eefd00c9f6c3120668c..c298ec117a86ddc1d86e0bbd1edc78f6b31ef07a 100644 (file)
--- a/res/micropolis.tcl
+++ b/res/micropolis.tcl
@@ -3101,8 +3101,10 @@ proc ShowSplashOf {head} {
 
 
 proc WithdrawSplashOf {head} {
-  set win WindowLink $head.splash]
-  wm withdraw $win
+  set win [WindowLink $head.splash]
+  if {$win != {}} {
+    wm withdraw $win
+  }
 }
 
 
@@ -3152,8 +3154,10 @@ proc ShowScenarioOf {head} {
 
 
 proc WithdrawScenarioOf {head} {
-  set win WindowLink $head.scenario]
-  wm withdraw $win
+  set win [WindowLink $head.scenario]
+  if {$win != {}} {
+    wm withdraw $win
+  }
 }