'To JavaScript' does not work

[niujingqian]

When I open the page('vertical_playground.html'),
Click the button('To JavaScript'),
I got the error:
"
vertical_playground.html:133 Uncaught TypeError: Cannot read property 'workspaceToCode' of undefined
at toCode (vertical_playground.html:133)
at HTMLInputElement.onclick (vertical_playground.html:547)

"

Operating System and Browser

Window 7 and Google Chrome(59.0.3071.86)