Variables are stored case-insensitively. Internally they’re keyed as lower-case. Prefer simple names: user, path_out.

Any command string parameter can include $varName:

• $name expands to the variable value if present.
• If not present, the literal $name is kept (no crash).

Example:

set first = "Ada";
set last  = "Lovelace";
concat "$first ", "$last", full;
message "Hello, $full!";

• Buttons: button_<name>_text
• Labels: label_<name>_text
• Inputs: input_<name>_text (kept up-to-date on onChange)
• ListBoxes: listbox_<name>_item_<i>, listbox_<name>_count
• Panel children: prefix with panel_<panelName>_...

• Falsey: empty string, "0", "false" (case-insensitive).
• Everything else is truthy.

• == and != perform case-insensitive string comparison.
• < and > compare integers parsed from both sides.