addizionare 2 varibili prese da form

[pedrosque]

function calcolatotale(){
var x= document.form3.length;
var tot = document.formtot.totale.value;
var tot = 0;
for(count=0; count<x; count+=1){
if(document.form3.elements[count].checked){
var h = document.form3.elements[count].value;
tot = parseFloat(tot);
h = parseFloat(h);
tot = tot + h;
document.formtot.totale.value = tot;
}
}
}