Wordpress - Meta Field Update - wordpress

Question

I created a couple meta fields in Wordpress for a Custom Post Type. They are 'Price' and 'Details'. If I got to the 'edit post' page, and i change something in one of these fields, but then decide to just leave the page by hitting 'back' in the browser or closing the window, i get a warning from my browser "are you sure you want to leave the page?". When I hit 'Yes', it erases anything that's in those 2 fields, even what was previously stored before my editing.
Any idea why this could be?
Here's some of my code in functions.php:
add_action("admin_init", "admin_init");
function admin_init()
{
add_meta_box("price", "Price", "price_field", "product", "normal", "high");
add_meta_box("details", "Details", "details_field", "product", "normal", "high");
}
function price_field()
{
global $post;
$custom = get_post_custom($post->ID);
$price = $custom["price"][0];
?>
<label>Price: $</label>
<input name="price" value="<?php echo $price; ?>" />
<?php
}
function details_field()
{
global $post;
$custom = get_post_custom($post->ID);
$details = $custom["details"][0];
?>
<label>Details:</label>
<input name="details" rows='5' value="<?php echo $details; ?>" />
<?php
}
/*--------------------------------*/
/* Save PRICE and DETAILS fields */
/*--------------------------------*/
add_action('save_post', 'save_details');
function save_details()
{
global $post;
update_post_meta($post->ID, "price", $_POST["price"]);
update_post_meta($post->ID, "details", $_POST["details"]);
}

Answer 1

This is because you didnt add filtering in your save details method. Remember action hook "save_post" is also called once the post is auto save in draft even if you didnt click the update or the publish button. Try this
add_action('save_post', 'save_details');
function save_details($post_id){
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
return;
// uncomment if youre using nonce
//if ( !wp_verify_nonce( $_POST['my_noncename'], plugin_basename( __FILE__ ) ) )
// return;
// Check permissions
//change the "post" with your custom post type
if ( 'post' == $_POST['post_type'] )
{
if ( !current_user_can( 'edit_page', $post_id ) )
return;
}
else
{
if ( !current_user_can( 'edit_post', $post_id ) )
return;
}
//if success go to your process
//you can erase your global $post and dont use $post->ID rather change it with $post_id since its our parameter
update_post_meta($post_id, "price", $_POST["price"]);
update_post_meta($post_id, "details", $_POST["details"]);
}
NOTE: in if ( 'post' == $_POST['post_type'] ) line, change "post" to your post type