Código PHP:
if ((isset($_POST["MM_update"])) && ($_POST["MM_update"] == "form1")) {
// La parte del Upload del Logo de la Empresa
if(((!empty($_FILES['favicon']['name'])) || ($_FILES['favicon']['name']) != "") || ($campo_favicon == "" || empty($campo_favicon))){
if(is_uploaded_file($_FILES['favicon']['tmp_name'])){
move_uploaded_file($_FILES['favicon']['tmp_name'],'../site/images/'.$_FILES['favicon']['name']);
$favicon = $_FILES['favicon']['name'];
}
} else {
$Logofavicon = $campo_favicon;
}
}