var del=false;
function operazione()
{
var del= false;
var b = parseFloat(document.getElementById("display").value);
var c;
switch (op)
{
case "+":
c = a+b; break;
case "-":
c = a-b; break;
case "*":
c = a*b; break;
case "/":
c = a/b; break;
}
document.getElementById("display").value = ''+c;
del = true;
}
function segno()
{
var cr;
if (document.getElementById("display").value == "") document.getElementById("display").value = "0."
else
{
var stringa = document.getElementById("display").value;
var val = true;
for (i=1; i<stringa.length; i++)
{
if (stringa.charAt(i) == '.') val = false;
}
document.getElementById("display").value = ((val == true) ? document.getElementById("display").value+'.' :document.getElementById("display").value);
}
}
function cancel()
{
document.getElementById("display").value = '';
a = 0;
b = 0;
}
