A barberpole spinner

[clasqm]

OK, I'm missing something here. The code below should display a 50-pixel horizontal spinner in the bottom left corner. But it doesn't. It does not crash, it just does not display anything.

Code:

import spinner

    window open 100,100 to 500,280, "MainWindow", ProgramName$
    window set "MainWindow", "look", "floating"
    window set "MainWindow", "feel", "modal-app"
    window set "MainWindow", "flags","not-zoomable"
    window set "MainWindow", "flags","not-resizable"
    text 10,25 to 49,40, "URLlabel", "URL:", "MainWindow"
    text 10,68 to 52,88, "Submitlabel", "Submit", "MainWindow"
    text 10,105 to 59,125, "Resultslabel", "Result:", "MainWindow"
    
    draw rect  70,10 to 390,50, "MainWindow"
    Textedit 71,11 to 389,49, "URLField", 0,"MainWindow"
    Button 70, 60 to 390, 90, "tinyurlButton", "Submit this URL to tinyurl.com", "MainWindow"
    
    View 70, 100 to 390, 130, "ShortURLView", "MainWindow"
    
    new_spinner(10,147,50,0, "DuringCurl", "MainWindow")
    display_spinner("DuringCurl")
    spin("DuringCurl")
    
    Button 70, 140 to 280, 170, "copyButton", "Copy to clipboard", "MainWindow"
    option set "copyButton", "enabled", 0 //don't need this until we have a short URL
    Button 290, 140 to 390, 170, "aboutButton", "About", "MainWindow"

There's something here that I am not seeing/understanding.