How to add popup window in php ?

Question

display message for user then transaction complete....

Answer 1

https://www.codeproject.com/Questions/360379/How-to-create-popup-window-in-php

Answer 2

For a popup javascript is required. Put this in your header:

<script>
function myFunction()
{
alert("I am an alert box!"); // this is the message in ""
}
</script>
And this in your body:

<input type="button" onclick="myFunction()" value="Show alert box">

from the link below :
https://stackoverflow.com/questions/15659522/popup-window-in-php