Php post submit not updating
It took me ages to work out and I couldn't find the help I needed in google. Make sure your input items have the NAME attribute. The name attribute on your input controls is what $_POST uses to index the data and therefore show the results.
There's an earlier note here about correctly referencing elements in $_POST which is accurate.
Please read the manual section on Variables from external sources for more information and examples on using forms with PHP.
Remember also that using  as in index will cause a sequential numeric array to be created once the data is posted, so sometimes it's better to define your indexes explicitly.
I know it's a pretty basic thing but I had issues trying to access the $_POST variable on a form submission from my HTML page.
If you click "Reload" or "Refresh" on a page that you reached through a POST, it's almost always an error -- you shouldn't be posting the same comment twice -- which is why these pages aren't bookmarked or cached.
You should use the GET method when your form is, well, getting something off the server and not actually changing anything.
This simply means that it is available in all scopes throughout a script.