单击按钮后如何显示弹出确认

I'm still a learner on PHP.

I have a button, and it shall run a JavaScript after clicking it, but I want it to show an alert / pop up for users to confirm whether to continue or to abort.

Can I do the function in my PHP file in the button code?

<TD style='text-align:left;padding:0;margin:0;'>
    <INPUT type='button' onmouseup="javascript:JS1();" value='JS1'></INPUT>
</TD>

you need to make function and use confirm();

<TD style='text-align:left;padding:0;margin:0;'>
            <INPUT type='button' onmouseup="myFunction();" value='JS1'></INPUT>
        </TD>

And

<script>
function myFunction() {
    confirm("Please confrim");
}
</script>

Have you tried bootstrap modal?

https://www.w3schools.com/bootstrap/bootstrap_modal.asp

https://getbootstrap.com/docs/4.0/components/modal/

https://getbootstrap.com/docs/3.3/javascript/

I have provided 3 links. I think these might help you a little. Do a research and it won't be very hard. Good luck.

Writing code is not what is supposed here.

But, still following pseudo code and concepts should work.

Steps:

If you are using jQuery, bind the event of click. If you are using core Javscript, use onclick attribute.
In the onclick function, add a confirmation popup.
confirm() returns true if user selects yes, or else it will return false.
Now, you have to proceed only if true is returned by confirm().

And javascript code:

<script>
function JS1() {
 if (confirm('Your confirmation message')) {
  // Write your code of form submit/button click handler.
 }
 else {
  return false;
 }
}
</script>