0. Welcome to Bytes.
1. You want to look at javascript for that. Javascript handles actions once the page has been sent and the user is looking at it. To use PHP, you would need to send the page again, which would involve sending the form, but that's a bit overkill. AJAX is like a hybrid, but is not needed. So using javascript you can use user events (like clicking a radio button or changing a dropdown) to do something (like change your "amt" value).
2. Once your form has been submitted, the data from your form is sent in a $_POST array. To access your $_POST variables your would have something like:
So the name of the form element is the "key" of the array. If you haven't done much of this before you should really spend some time reading about PHP forms.
3. Again, this is form handling, so once your form is finished, you can set what it displays and include something like:
- if ($successful) {
echo "Thanks for your \$$amt!";
}
The "\$" is to escape the $ character (which is usually for variables) and the next $amt is for the variable previously defined.
4. You said that the input you described what your submit button? It's type is "hidden" so it will not display, and if it was a submit button teh type would be "submit"? Which do you want?
