Radius-Circle

function calc(form) {

var radius = parseFloat(form.radius.value);

var volume = (4/3) * Math.PI * Math.pow(radius,3); document.getElementById("volume").innerHTML = chopTo4(volume);

var c = document.getElementById("mycanvas"); var ctx = c.getContext("2d"); ctx.beginPath(); ctx.arc(200,200,radius,0,2*Math.PI); ctx.stroke(); }

function chopTo4(raw) { strRaw = raw.toString(); if(strRaw.length - strRaw.indexOf(".") > 4) strRaw = strRaw.substring(0,strRaw.indexOf(".") + 5); return strRaw; } // openclass // function surligne(champ, erreur) { if(erreur) champ.style.backgroundColor = "#FF0000";

else champ.style.backgroundColor = "#00FF00"; }

function verifPseudo(champ) { if(champ.value < 0 || champ.value > 200 || champ.value*0 !=0 || champ.value == "" ) { surligne(champ, true); alerty();
return false; } else { surligne(champ, false); return true; } }

function alerty () { alert('Error,print a number between 0 and 200 !') }

function cleary (context,canvas) { canvas = document.getElementById("mycanvas"); ctx = canvas.getContext("2d"); ctx.clearRect(0, 0, canvas.width, canvas.height); }