I am new to php, just made a simple calculator. when I don't select the radio buttons; a notice come up.
Notice: Undefined index: r in E:\MY LOCAL SERVER\htdocs\php practise\calculator-form-advanced.php on line 59
Also I want show results in this input section
<p>
<label for="result">Result</label>
<input type="text" value="" />
</p>
---
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<body>
<form id="form1" name="form1" method="post" action="">
<p>
<label for="num1">Number 1</label>
<input type="text" name="num1" id="num1" />
</p>
<p>
<label for="num2">Number 2</label>
<input type="text" name="num2" id="num2" />
</p>
<p>
<input type="radio" name="r" id="add" value="add" />
<label for="add">Addition</label>
</p>
<p>
<input type="radio" name="r" id="sub" value="sub" />
<label for="sub">Subtraction</label>
</p>
<p>
<input type="radio" name="r" id="mul" value="mul" />
<label for="mul">Multiplication</label>
</p>
<p>
<input type="radio" name="r" id="div" value="div" />
<label for="div">Division</label>
</p>
<p>
<input type="submit" name="submit" id="submit" value="Submit" />
</p>
<p>
<label for="result">Result</label>
<input type="text" value="" />
</p>
</form>
<?php
if (isset($_POST["submit"]))
{
$num1 = $_POST['num1'];
$num2 = $_POST['num2'];
$action = $_POST['r'];
if ( $num1==''|| $num2=='' || $action=='' )
echo 'Something missing';
else {
switch ($action)
{
case "add":
{
$result = $num1 + $num2;
echo $result;
break;
}
case "sub":
{
$result = $num1 - $num2;
echo $result;
break;
}case "mul":
{
$result = $num1 * $num2;
echo $result;
break;
}case "div":
{
$result = $num1 / $num2;
echo $result;
break;
}
}
}
}
?>
</body>
</html>