如何在php和js组合中使用alert

have a need to alert through php,
I have the code below. Problem is that it works as long as I dont use header redirect. But as soon as I use it..I loose alert.

echo "I will do some functions here in php";  
if($value == 1){  
alert('ok working');  
}  
header(location: 'someOtherpagethanthis.php');  

A redirect instructs the browser to immediately fire a brand new request. The response body with the alert will be ignored. You may want to use JS instead to fire a new request after the alert.

if ($value == 1) {  
    alert('ok working');  
    window.location = 'someOtherpagethanthis.php';
}