Password protection

Hi there

I have a password protection message on some of my posts _I am using the parament theme) – how can I change this to say:
To see this password protected post please subscribe

I pasted the following into the functions php earlier and lost my site so how can I avoid doing that in future?

<?php
function my_password_form() {
global $post;
$label = ‘pwbox-‘.( empty( $post->ID ) ? rand() : $post->ID );
$o = ‘<form action=”‘ . esc_url( site_url( ‘wp-login.php?action=postpass’, ‘login_post’ ) ) . ‘” method=”post”>
‘ . __( “To view this protected post, enter the password below:” ) . ‘
<label for=”‘ . $label . ‘”>’ . __( “Password:” ) . ‘ </label><input name=”post_password” id=”‘ . $label . ‘” type=”password” size=”20″ maxlength=”20″ /><input type=”submit” name=”Submit” value=”‘ . esc_attr__( “Submit” ) . ‘” />
</form>
‘;
return $o;
}
add_filter( ‘the_password_form’, ‘my_password_form’ );
?>