Reduce size of sencha-touch.js

I have made a basic WAP site with sencha.
the size of the core file sencha-touch.js is 366kb, which is very large or mobile platform.
i used jsmin(which minifies and compresses), this brought down the size to 100kb.
using jsbuilder i tried to remove unwanted javascript but hardly another 10kb of size reduction.

How can we bring the size further down to say 20kb?
Please help

I tried jsmin, and didn't work out.
sencha-touch.js 360+k is already minfied, how did you do that?