Delay custom button using javascript

I have a survey block with a multi-page timer built in javascript, ensuring that respondents are auto-forwarded after ten minutes. The code hides the next button and presents a "check"-button to participants to advance within the block. The code runs nicely.

However, I'd also like to hide the "check"-button a few seconds for every new page. The code below seemed initially ok to me; it displays the "check"-button after the participant has been on the page for three seconds, but when I click on the "check"-button nothing happens. Any ideas what might be going wrong here?

Many thanks!

Ing

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this.hideNextButton();

var delayInMilliseconds = 3000;

setTimeout(function() {
$('NextButton').insert({before: "<input id=\\"checkButton\\" type=\\"button\\" value=\\" >> \\" title=\\" >> \\">"});
}, delayInMilliseconds);