php safe output -

i'm trying make "remember fields" thingy, if there 1 error won't have fill in whole form again. how can make output safe?

example:

<input type="text" name="email" value="<?php echo (isset($_post['email'])) ? htmlspecialchars($_post['email']) : ''; ?>" /> 

if types in " ' " (without quotes) example get:

warning: mysql_result() expects parameter 1 resource, boolean given in c:\wamp\www\pages\register.php on line 55 

so tried:

<input type="text" name="email" value="<?php echo (isset($_post['email'])) ? mysql_real_escape_string($_post['email']) : ''; ?>" /> 

then adds lot of //////.

what should do?

i'm noob yes. thought htmlspecialchars made user input safe?

it depends on context.

htmlspecialchars() friend in html.

mysql_real_escape_string() friend in mysql.

update

you run $_post through htmlspecialchars() first this...

$encodedhtmlpost = array_map('htmlspecialchars', $_post);