modified:   calculate.js
	modified:   index.html
	new file:   modules/bt0.js
	new file:   modules/bt1.js
	new file:   modules/bt2.js
	new file:   modules/bt3.js
	new file:   modules/bt4.js
	new file:   modules/bt5.js
	new file:   modules/bt6.js
	new file:   modules/bt7.js
	new file:   modules/init.css
	new file:   modules/init.js