i m new in php i make two pages first was first.php
the second was insert.php the codes are below but it show Notice: Undefined index:
how to remove this error
thanks

first page

<!DOCTYPE html>
<html>
<body>
<form id="firstform" action="insert.php" method="post">
<center> My First Page in PHP </center>
<center>Name:<input type="text" id="name" size=20>
FatherName: <input type="text" id="fname" size=20>
Address:<input type="text" id="add" size=20>
<input type="submit" name="sub">
</form>
</body>
</html>

insert page

<html>
<body>
<?php

$con=mysqli_connect("localhost","root","khan","first");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="INSERT INTO bio(name, fathername , address)
VALUES
('$_POST[name]','$_POST[fname]','$_POST[add]')";

if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
echo "1 record added";

mysqli_close($con);
?>
</body>
</html>