.EXT file cann't selected for the tone

[sudeep_mib]

Hi,
I've taken some .midi files from my friend ir. In which oneof the file contains the file name like this 'filename.midi.Ext'
when i tried to use thi file for wake up alarm. They doesn't find when i browsing them through wake up menu or when i'm asigning .midi to the call.but when when i'm seen them from gallery menu they will see & i can assign them by going on them & then By using option 'set as ringtone'
For which purpose .ext is used

Pleae help


Thanks