function displaysfpm(form)
{
  var dia = diam1.value
  var rpm = rpm1.value
  var sfm = 0.262*dia*rpm
  wyn1.value = sfm

}
function displayrpm(form)
{
  var sfm = sfpm2.value
  var dia = diam2.value
  var rpm = ((3.82)*sfm)/dia
  wyn2.value = rpm

}
function displayipm(form)
{
  var ipt = ipt3.value
  var teeth = teeth3.value
  var rpm = rpm3.value
  var ipm = ipt * teeth * rpm
  wyn3.value = ipm

}
function displayfpt(form)
{
  var ipm = ipm4.value
  var rpm = rpm4.value
  var teeth = teeth4.value
  var fpt = ipm / (teeth * rpm)
  wyn4.value = fpt

}
function displayipt(form)
{
  var rpm = rpm4.value
  var ipm = ipm4.value
  var teeth = teeth4.value
  var ipt = rpm*ipm*teeth
  wyn4.value = ipt
}
function displayfpr(form)
{
  var ipm = ipm5.value
  var rpm = rpm5.value
  var fpr = ipm / rpm
  wyn5.value = fpr

}
function change(co)
{
 tab_ch.style.display = "none";
 if (co==1) {
 	tab_sfpm.style.display = "";
	rpm1.focus()
 }
 else if (co == 2){
 	tab_rpm.style.display = "";
	sfpm2.focus();
 }
 else if (co == 3){
 	tab_ipm.style.display = "";
	rpm3.focus();
 }
 else if (co == 4){
 	tab_fpt.style.display = "";
	ipm4.focus();
 }
 else if (co == 5){
 	tab_fpr.style.display = "";
	ipm5.focus();
 }
 else if (co == 0){
 	tab_sfpm.style.display = "none";
	tab_rpm.style.display = "none";
	tab_ipm.style.display = "none";
	tab_fpt.style.display = "none";
	tab_fpr.style.display = "none";
	tab_ch.style.display = "";
 }
}