PHP verhindern die Wiederaufnahme der Form
<!---
Add this to your HTML and it will prevent a pop up.
Found the answer from the link below.
https://stackoverflow.com/questions/6320113/how-to-prevent-form-resubmission-when-page-is-refreshed-f5-ctrlr
--->
<script>
if(window.history.replaceState)
{
window.history.replaceState(null, null, window.location.href);
}
</script>
Button