custom fields for products

hi,

i add a custom field for a product, i gave a title , and then i write a description to the product and thats great, the prblem is that there is products without the need to add a description to the new field, but the title is showing up on all products pages. how can i make that it will be shown just at the products that i add a desc to the field.

i done it, its not working now at all.
BTW i did it via FTP beacase from the view display i got a refuse to edit the file (even that the permission is 777), any way via ftp i did it but now not the title or the description show up.

maybe i didnt explain my self clearly.
now i am using the essential, at the essential i have a possibility to add a custom field, my request was about the custom field, now i cant see the custom field that i added.

yes, but now when i am adding content to the product in the custom field i dont see nothing.
i will elaborate:
thats exactly what i ask to remove the custom fields when the content of the custom field is empthy, but now even when i am adding text to the custom field nothing is show at the product page for the customers.

now i just see the word; "SPECIFICATIONS"

now its working, i dont know how?