How to add input text attribute on order by bar Magento

Sadly you cant do this but I have found a solution.The solution consist converting your input text in to a select field.

1.-Create a new input select field.
2.-Copy and paste this code in a new php file.Download here
3.-Edit the first variables with your own attributes to change and save the file as changeattr.php .
4.-Open the terminal and get over the root magento's folder.
Example on windows
cd c:/xampp/htdocs/magento

Example on linux

cd /var/www/magento

4.-Once you are on the folder type in the terminal   php changeattr.php  .
5.-The file is going to save all the values used in a .cvs in order to export to the new attribute,and the script is in charged of all the hard work.