function MakeArray(n)
{
  this.length = n;
  for (var i = 1; i <= n; i++)
  	this[i] = 0;
  return this;
}

speedVar = new MakeArray(5);
speedVar[1] = "2.84321";
speedVar[2] = "5.68";
speedVar[3] = "11.3";
speedVar[4] = "85.289";
speedVar[5] = "153.520";

function compute(form, mult)
{
    var theNum = form.size.value;
    var numFormat = /(^\d+$)/;
    if (!numFormat.test(theNum))
            alert("Prosze wprowadzic ilosc MB w postaci dziesietnej.");
    else {
	for (i=1; i < 11; i++) {
	    if (form.size.value==null||form.size.value.length==0)
		form.size.value=0;
	    if (form[i+"hour"].value==null||form[i+"hour"].value.length==0)
		form[i+"hour"].value=0;
	    if (form[i+"minute"].value==null||form[i+"minute"].value.length==0)
		form[i+"minute"].value=0;
	    if (mult != 0 && form.size.value != 0) {
		with (Math) {
		    var speed = speedVar[i];
		    var TotalTime = ((form.size.value*mult)/speed);
		    var TotalHours = floor((TotalTime/3600));
		    var TotalHoursMod = (TotalTime%3600);
		    var TotalMin = ceil(TotalHoursMod/60);
		    var TotalMinMod = (TotalHoursMod%60);
		    form[i+"hour"].value=TotalHours;
		    form[i+"minute"].value=TotalMin;
		}
	    }
	}
    }
    return;
}