Micropolis - startup screen

Adapting the startup screen, calling up different images and forking between the first two scenarios. File res/micropolis.tcl
Edited the content of the Messages that show up on clicks on different scenarios. It cannot be empty by the way Message variable is defined.
proc Message {id color title msg {props {}}} {
global Messages
set Messages($id) [list $color $title $msg $props]
}
The color probably refers to the title and is not displayed anywhere.
I expected these lines to be responsible for the size of the screen where the message appears
set ScenarioPanelWidth 420
set ScenarioPanelHeight 300
but it didn't change at all after I tried different numbers.