php - how to encrypt passwords so that it cannot be easily cracked?

I have used md5() for this purpose

// username and password sent from form 

$username=$_POST['myusername']; 
$password=$_POST['mypassword']; 
$encrypted_password=md5($password);

$sql="SELECT * FROM $tbl_name WHERE username='$username' and password='$encrypted_password'";
$result=mysql_query($sql);

But I heard that it is not safe.
I'm a beginner so please suggest me a good password encryting method? also if post data was intercepted would it be visible as plaintext?

Answer

I'm a beginner so please suggest me a good password encryting method

Make use of crypt() instead of md5()

$hashed_password = crypt('mypassword'); // let the salt be automatically generated
if (crypt($user_input, $hashed_password) == $hashed_password) {
   echo "Password verified!";
}
?>

Some examples from the PHP Manual

also if post data was intercepted would it be visible as plaintext ?

Ofcourse! If you are really concerned about that, Get an SSL Certificate configured on your domain.