adding price, blank white screen

Hi,

A blank page does not help us to determine what could be the problem so if you get a blank page (an entire white screen without anything written on it), please make sure that your PHP configuration enables you to see errors and if not, edit your php.ini file and search for the string parameter display_errors.
This parameter should be turned On : display_errors = On.
If it's not the case, please edit your php.ini file, modify this line, save your file and then restart your server and try again to display the page. You should not see a blank screen anymore and the error message will help us a lot to fix the problem.