well I did it, it works perfectly, thank you for all the guidance I recieved.
$tmp_html = '<input type="text" name="id[' . TEXT_PREFIX . $products_options_names->fields['products_options_id'] . ']" size="' . $products_options_names->fields['products_options_size'] .'" maxlength="' . $products_options_names->fields['products_options_length'] . '" value="';
// BEGIN THE CODE I ADDED TO CHANGE THE VALUE OF TEXT FIELDS
if ($products_options_names->fields['products_options_id'] == "60") {
$tmp_html .= htmlspecialchars($_GET['imgnumber']);
}else {
$tmp_html .= htmlspecialchars($tmp_value);
}
// END THE CODE I CREATED
$tmp_html .= '" id="' . 'attrib-' . $products_options_names->fields['products_options_id'] . '-' . $products_options_value_id . '" /> ';