i have a form that submits data to a database, i have a function that looks like this:

//connect 
foreach ($_POST as $key => $value) {
    $_POST[$key] = mysql_real_escape_string($value);
}

now when i post, SOMETIMES i get an error that says this:

Allowed memory size of 268435456 bytes exhausted

i figured out that when i do a linebreak, or press enter in the message field, then that is when it causes the error, otherwise it works normal. any ideas?