Returns a named POST parameter value.
Returns an element with a name specified in the first parameter from the
$_POST array.
If the element is not found, returns default value, optionally specified in the second parameter.
This function is useful for form processing.
The following code extracts the
name POST element and if there is no such en element, uses string "John".
$name = post('name', 'John');
This function is a shortcut for
Phpr_Request::post() method.