edit script of card button "example" --so you can see the script
end mouseUp
-- part 9 (button)
-- low flags: 00
-- high flags: 0001
-- rect: left=206 top=297 right=320 bottom=244
-- title width / last selected line: 0
-- icon id / first selected line: 0 / 0
-- text alignment: 1
-- font id: 0
-- text size: 12
-- style flags: 0
-- line height: 16
-- part name:
-- part contents for background part 1
----- text -----
Once HyperCard finds a handler for the message sent and begins performing the commands in a script, those commands are carried out sequentially from first to last. You can modify the order or pass control using five control structures: If, Repeat, Exit, Send and Pass.
If <true or false expression> then
<command>
<command>
else
<command>
<command>
end if
-- part contents for background part 2
----- text -----
Control structures (1)
-- part contents for background part 44
----- text -----
if...then
else
end if
-- part contents for background part 43
----- text -----
267,189
-- part contents for card part 4
----- text -----
An expression is a piece of HyperTalk that has a value. In this example, the result of the expression must be either true or false.