function pp(concwat)
  {
  var u1 = concwat.corf[0].checked;
  var u2 = concwat.corf[1].checked;
  var u3 = concwat.corf[2].checked;
  if (u1 == true)
    {
    var dp = parseInt((concwat.dewpoint.value-32)/1.8);
    }
  else
    {
    if (u3 == true)
      {
      var dp = parseInt(concwat.dewpoint.value-273.14);
      }
    else
      {
      var dp = parseInt(concwat.dewpoint.value);
      }
    }
  var pd1 = (8.1332 - 1762.39/(dp+235.66));
  pd = Math.pow(10, pd1);
  var concres = pd * 1316;
  abres = concres * 0.000804;
  concwat.partpres.value = (Math.round(pd*10))/10;
  concwat.Ppm.value = Math.round(concres);
  concwat.Ab.value = (Math.round(abres*10))/10;
  }

function clearall(form)
  {
  form.partpres.value = "";
  form.dewpoint.value = "";
  form.Ppm.value = "";
  form.Ab.value ="";
  }