function EnrichCalc(form)
{
  var v1 = parseFloat(form.i1.value, 10)
  var v2 = parseFloat(form.i2.value, 10)
  var v3 = parseFloat(form.i3.value, 10)
  var v4 = parseFloat(form.i4.value, 10)
  var v5 = parseFloat(form.i5.value, 10)
  var v6 = parseFloat(form.i6.value, 10)
  var x1 = 1-v1-v2
  var x2 = 2.01594 + 15.99491*x1 + 16.999131*v2 + 17.99916*v1
  var x3 = 100*((v1*v4/(2*1.00797+((1-v2-v1)*15.99491)+v2*16.999131+v1*17.99916))+v5*0.0001248415283+v6*0.000113791838)/((v4/(2*1.00797+((1-v2-v1)*15.99491)+v2*16.999131+v1*17.99916))+v5*0.0499366113+v6*0.0555082137);
  var x4 = 100*((0.00030*v4/(2*1.00797+((1-v2-v1)*15.99491)+v2*16.999131+v1*17.99916))+(v5*v3*2/(2.01234*v3+18.01505))+v6*1.665246e-5)/((2*v4/(2*1.00797+((1-v2-v1)*15.99491)+v2*16.999131+v1*17.99916))+(2*v5/(2.01234*v3+18.01505))+v6*0.1110164274);
  var x5 = 2;
  var y1 = Math.round(x4*Math.pow(10,x5))/Math.pow(10,x5);
  var y2 = Math.round(x3*Math.pow(10,x5))/Math.pow(10,x5);
  form.O18_Enrichment.value = y2
  form.D_Enrichment.value = y1
}