Very Simple problem about $_POST object

[qadeer]

I have a code as below

foreach($_POST as $varname => $value)

      {
      $list[$varname] = $value;
      }

[/COLOR]

But when I execute it I get the following error

Invalid argument supplied for foreach() in ......

I also have tried $HTTP_POST_VARS instead $_POST

[laserlight]

if (!empty($_POST)) {
	foreach ($_POST as $varname => $value) {
		$list[$varname] = $value;
	}
}

though why not use $POST directly instead of using some $list array?
Conversely, $list = $POST; might also work, though again would be redundant.