foreach($_POST['your_array_here'] as &$val) {
     $val = mysql_real_escape_string($val);
}

// FORM FIELDS EXAMPLE
<input type="text" name="field[p_name]" id="field[p_name]" />
<input type="text" name="field[p_email]" id="field[p_email]" />

// PHP PROCESSING EXAMPLE
function process_form() {
     foreach($_POST['field'] as &$val) {
          $val = mysql_real_escape_string($val);
     }

     extract($_POST['field']);

     $sql = "INSERT INTO my_table (name, email) VALUES ('$p_name', '$p_email')";

     mysql_query($sql) or die ('An error has occurred');
}

foreach($_POST['your_array_here'] as &$val) {
     $val = mysql_real_escape_string($val);
}

// FORM FIELDS EXAMPLE
<input type="text" name="field[p_name]" id="field[p_name]" />
<input type="text" name="field[p_email]" id="field[p_email]" />

// PHP PROCESSING EXAMPLE
function process_form() {
     foreach($_POST['field'] as &$val) {
          $val = mysql_real_escape_string($val);
     }

     extract($_POST['field']);

     $sql = "INSERT INTO my_table (name, email) VALUES ('$p_name', '$p_email');

     mysql_query($sql) or die ('An error has occurred');
}

This is useful for escaping multiple values in a POST array.

Escaping Multiple Post Values for MySQL with PHP

mysql, php, security

PHP