How do you add custom ringtones for text messaging?

[KonstantlyKyle]

I added custom ringtones for calling, but they won't transfer over to my text ringtones. :/
I'm not looking to give each person their own ringtone, I just want to change the ringtone for every time I get a text.

Help?

I have an SD Card, and a USB Cord [of course].​

 

[lmc05]

I'm not sure that it's possible....

 

[KonstantlyKyle]

I'm not sure that it's possible....

I'm sure there's a way....
My old Cliq could do it.​