javascript function to do maths

dummy maths equation just to get it working
to calculate something, and put result in a
html element using .innerHTML
Plus the HTML element tp put it in

HTML has a slider and a drop down list from jquery mobile
fix typos
add more sliders for more parameters

used mini spiders to take up less screen space
the slider values aren't used yet for any maths
used slider steps for sensible increment values.
Edited the wording a little.