ปัญหาเกี่ยวกับ Tag Select และ Array และการบันทึกค่าลง Database

<SELECT NAME="os">
	<option value="<?=$arr[HW][hw_os];?>" selected><?=$arr[HW][hw_os];?></option>
	<option value="Linux">Linux</option>
	<option value="Linux">Linux 2</option>
	<option value="Android">Android</option>
	<option value="Windows Phone">Windows Phone</option>
	<option value="IOS">IOS</option>
	<option value="Mac Apple">Mac Apple</option>
</SELECT>	

<?
	$arrayOS = array(
		"Linux"				=> array("Linux", "Linux 2"),
		"Android"			=> array("Android"),
		"IOS"				=> array("IOS", "IOS10", "IOS20"),
		"Mac Apple"			=> array("Mac Apple"),							
	);							
	$arrayCheck="";
	foreach($arrayOS as $arrayOSShowTypes => $arrayOSShowModels) {
		foreach($arrayOSShowModels as $arrayOSCheck) {
			if(strcasecmp($arr[HW][hw_os], $arrayOSCheck) == 0) { $arrayCheck = "1"; }
		}
	}
?>

<SELECT NAME="os">
<?
	if($arrayCheck == "1") {
		foreach($arrayOS as $arrayOSShowTypes => $arrayOSShowModels) {
			foreach($arrayOSShowModels as $arrayOSCheck) {
				echo '<option value='.$arrayOSCheck.'';
				if (strcasecmp($arr[HW][hw_os], $arrayOSCheck) == 0) { echo " Selected"; }
				echo '>'.$arrayOSCheck.'</option>';
			}
	}
	} else {
		echo '<option value='.$arr[HW][hw_os].' Selected>'.$arr[HW][hw_os].'</option>';
		foreach($arrayOS as $arrayOSShowTypes => $arrayOSShowModels) {
			foreach($arrayOSShowModels as $arrayOSCheck) {
				echo $arrayOSCheck;
				echo '<option value='.$arrayOSCheck.'>'.$arrayOSCheck.'</option>';
			}
		}
	}
?>
</SELECT>