<!-- Chain length calculator copyright epicidiot.com -->

function chaincalc(form) {
var units=eval(form.R1[0].checked)
var stay=eval(form.stay.value)
var front=eval(form.front.value)
var rear=eval(form.rear.value)

if( stay <= 0 || front <= 0 || rear <= 0 )
  return

if( units == false )
  stay = stay / 2.54
  
len= 2*(stay) + (front/4) + (rear/4) + ((front - rear) * (front - rear) * (0.01275) * (1/stay)) + 1


if( units ) {
  form.ans_length.value = Math.ceil( len )
  form.ans_units.value = "inches"
  }
else {
  form.ans_length.value = Math.ceil( len ) * 2.54
  form.ans_units.value = "centimeters"
  }

form.ans_links.value = Math.ceil( len )

self.location.href = "#results"

}