Default argument for Volume.alfredworkflow

[stackoverflow1024]

Hi BaksiLi,

This Alfred workflow is really a handy way to adjust system volume, however due to high frequency, usually the less keystroke the better, so is there anyway we can default the argument?
For example, when user just typing vol, it would default to vol 15 as an example, without typing extra characters.

I tried to modify your workflow script, but if add one more if condition on top of everything, seems other branches never get a chance to execute.
Could you help with this?
Thanks.