Untitled

<!DOCTYPE html>
<html lang="de">
<head>
<meta charset="utf-8">
<title>dEn Cliqulatoz</title>
<h1>THe KLaCULATIOR</h1>
</head>
<body bgcolor="#FF00FF" background="http://bestanimations.com/Animals/Birds/Parrots/animated-parrot-gif-2.gif">

    <form action="" method="Post">
<p>n1:<br/>
        <input type="text" name="n1" value="<?PHP if(!empty($_POST['n1']))echo $_POST['n1']?>"><br><br>
<p>n2:<br/>
        <input type="text" name="n2" value="<?PHP if(!empty($_POST['n2']))echo $_POST['n2']?>">
        <br>

<button type="submit" name="group1" id="add" value="add">+</button>
<button type="submit" name="group1" id="subtract" value="subtract">-</button>
<button type="submit" name="group1" id="times" value="times">*</button>
<p>
<button type="submit" name="group1" id="divide" value="divide">/</button>
<button type="submit" name="group1" id="force" value="force">^</button>
<button type="submit" name="group1" id="sqrt" value="sqrt">²√</button>
<!-- <button type="submit" name="group1" id="xrt" value="divide">/</button>
 <button type="submit" name="group1" id="divide" value="divide">/</button> -->

    </form>


<p>
answer:
<p>
<h1>
<?php
/*
if (!empty($_POST['n1'])){
$n1 = $_POST['n1'];
$n2 = $_POST['n2'];
else if($_POST['group1'] == 'sqrt') {
echo sqrt($n1);
}
else if(!empty($_POST['n1']) && !empty($_POST['n2'])){

$n1 = $_POST['n1'];
$n2 = $_POST['n2'];
if($_POST['group1'] == 'add') {
echo $n1 + $n2;
}
else if($_POST['group1'] == 'subtract') {
echo $n1 - $n2;
}
else if($_POST['group1'] == 'times') {
echo $n1 * $n2;
}
else if($_POST['group1'] == 'divide') {
echo $n1 / $n2;
}
else if($_POST['group1'] == 'force') {
echo pow($n1 , $n2);
}
}
}
else{}
*/
// if(!empty($_POST['n1']) && !empty($_POST['n2'])){
switch($_POST["group1"]){
    case "add":
        echo ($n1 + $n2);
        break;
    case "subtract":
        echo ($n1 - $n2);
        break;
    case "times":
        echo ($n1 * $n2);
        break;
    case "divide":
        echo ($n1 / $n2);
        break;
    case "force":
        echo (pow($n1, $n2));
        break;
    case "sqrt":
        echo (sqrt($n1));
        break;
//  case(){$n1 $n2}
//  case(){$n1 $n2}

}

// else{}
?>

</h1>
</form>
</body>
</html>