need to convert field names into array for form submission

How would I organize this block in order to convert it into an array for my form field names. For instance if my field has: <p>Home Phone Number:</p> <input maxlength="6" size="6" name="area_code" id="area_code" value="{$_POST['area_code']}"> &nbsp; <input maxlength="6" size="6" name="phone_exchange" id="phone_exchange" value="{$_POST['phone_exchange']}"> &nbsp; <input maxlength="10" size="10" name="last_4_digits" id="last_4_digits" value="{$_POST['last_4_digits']}"> &nbsp; I would want something to return an error stating that the phone number was not completed and not that the field last_4_digits was not entered. I believe this can be done with an array. my error block code is: function check($fieldname) { global $err_msg; if($_POST[$fieldname] == "") { if ( !isset($err_msg)) { $err_msg = "<div class='red'>You haven't entered your " . str_replace("_", " ", $fieldname) . "!</div><br />"; } elseif ( isset($err_msg)) { $err_msg .="<div class='red'>You haven't entered your " . str_replace("_", " ", $fieldname) . "!</div><br />"; } } return $err_msg; } any assistance is greatly appreciated! -- ::Bruce::