HTTP_POST_VARS is an array. It contains whatever data which were POSTed to PHP.
If you have a form which POSTs form-data to PHP, then that data will be available in the HTTP_POST_VARS variable (as well as directly in the normal page scope).
If you are looking for a variable called myVariable which should be POSTed to your script, then you may look for it like this:
if ($HTTP_POST_VARS['myVariable']=='horse')
{
// do something
} else {
// do something else
}
The HTTP_POST_VARS, HTTP_GET_VARS and HTTP_COOKIE_VARS arrays makes it possible to select specifically what external data source to use. If you don't care wether the data came from a POST, GET or a cookie, then you may just use the variable "directly"; in the above example, that would mean:
if ($myVariable=='horse')
{
// do something
} else {
// do something else
}
