function laske(arg,nimi,kerta){
var pt_hyoty = 'pt_hyoty'+arg;
var pt_arvo = 'pt_arvo'+arg;
var pt_kk = 'pt_kk'+arg;
var pt_lkm = 'pt_lkm'+arg;
var pt_vaik = 'pt_vaik'+arg;
var e_pt_hyoty = document.getElementById(pt_hyoty);
var e_pt_arvo = document.getElementById(pt_arvo);
var e_pt_lkm = document.getElementById(pt_lkm);
var e_pt_vaik = document.getElementById(pt_vaik);
var e_pt_kk = document.getElementById(pt_kk);
var reason = "";

e_pt_lkm.value=e_pt_lkm.value.replace (",",".");
e_pt_vaik.value=e_pt_vaik.value.replace (",",".");
e_pt_kk.value=e_pt_kk.value.replace (",", ".");
e_pt_arvo.value=e_pt_arvo.value.replace (",", ".");

reason += validoi(e_pt_lkm);
reason += validoi(e_pt_vaik);
reason += validoi(e_pt_kk);
reason += validoi(e_pt_arvo);
if (reason != "") {
alert("Lomakkeella puutteilla:\n" + reason);
return false;
}
if (kerta==0){
var hyoty=parseInt(parseFloat(e_pt_lkm.value)*parseFloat(e_pt_arvo.value)*parseFloat(e_pt_kk.value)*0.01*parseFloat(e_pt_vaik.value)*12*100)/100;
}
else
{
var hyoty=parseInt(parseFloat(e_pt_lkm.value)*parseFloat(e_pt_arvo.value)*parseFloat(e_pt_kk.value)*0.01*parseFloat(e_pt_vaik.value)*100)/100;
}
e_pt_hyoty.value=hyoty;
pageTracker._trackPageview("/laskurit/Hyoty/"+nimi+"_"+arg+"/"+parseInt(hyoty/1000)*1000);
}


function validoi(fld) {
var error = "";
if (fld.value == "") {
error = "Anna arvo\n";
fld.style.background = 'Yellow';
} else if (isNaN(parseFloat(fld.value))) {
error = "Ilmoita arvo numeromuodossa\n";
fld.style.background = 'Yellow';
} else {fld.style.background = '#ffffff';}
return error;
}