<!-- Author: Brian Mackenzie -->
<!-- Date: 6th December 2006 -->
<!-- Version: 1.0 -->

function calculate()
{
  var conv = document.stride.conv.value;
  var con = document.stride.con.options[document.stride.con.selectedIndex].value;
  
  if (con=='percent')
    {
      r1=Math.atan(conv/100)/0.017453293;
      document.stride.ans2.value=nt2dp(r1,1);
      document.stride.ans3.value="degrees";
    }

  else

    {
      r1=Math.tan(conv*0.017453293)*100;
      document.stride.ans3.value="percent";
      document.stride.ans2.value=nt2dp(r1,1);
    }
}

function valclear()
{
  document.stride.ans2.value = "";
  document.stride.ans3.value = "";
}

function nt2dp(num,dp)
{
<!-- rounds num to dp decimal places -->
  num=num*1+(0.55/Math.pow(10,dp));
  if (dp>0) dp=dp+1;
  b=Math.floor(num).toString().length+dp;
  return num.toString().substr(0,b);
}