Hello, you can try something like:
<?php
$model_name = get_field('model_name');
switch ($model_name) {
case 'iphone':
/* if no page output / print / echo to this function */
$redirect = "http://www.yourlinkredirect.com";
header("location:$redirect");
break;
case 'samsung':
/* with javascript help */
echo '<script language="JavaScript">
window.location="http://www.yourlinkredirect.com";
</script> '
break;
case 'others':
/* ... */
break;
}
?>
I hope that helps, hug…