Intro with FORM

<html>
<head>
<title> Web Programming </title>
</head>
<body>

Selamat pagi PHP!!!<br>
<?php
    echo "Tarikh ".date('D, d M Y');
?>
<p>Variables</p>
<?php
    //php vaiable
    $username="ali";
    $password="ali123";
    //display values
    echo "Hi username $username <br>";
    //concatenation
    echo "with password ". $password;
?>
<br>
<h3>Form input </h3>
<form method="get" action="">
    Number1
    <input name="n1" type="text"><br>
    Number2
    <input name="n2" type="text"><br>
    <input type="submit" value="ADD">
</form>
<br>Answer:
<?php
    //capture data from textbox
    $n1=$_GET['n1'];
    $n2=$_GET['n2'];
    //display result
    echo "$n1 + $n2 = ".$n1+$n2;
?>

</body>
</html>