html - $_POST undefined index PHP error

My html code which receives the string:

    


    
    

    Suggestion: 
    

My PHP which processes it: (process.php)

    if ($_POST["sgst"]=="john") {
        echo "john";
    } else {
        echo "someone";

    }
?>

I am getting the error

Notice: Undefined index: sgst in C:\xampp\htdocs\test\process.php on line 2

Can anyone tell me what is causing the error?

Answer

You're re-using the action attribute on the form element:

I'm surprised the form is even posting at all given that. Though given the symptoms it seems to at least be enough to confuse the POST. I think you meant to use the method attribute:

A couple other notes:

• You'll want to make use of isset() in your server-side code. The code shouldn't assume that all values will be posted, since the server can't control what a client sends it. Best to explicitly validate the data coming in before using it.


• font elements are pretty dated, and if they're not officially deprecated they should be :) CSS styling would be the way to go for client-side UI styles.