function KeepCount() {

var NewCount = 0

if (document.joe.Quantitydisc1.checked)
{NewCount = NewCount + 1}

if (document.joe.Quantitydisc2.checked)
{NewCount = NewCount + 1}

if (document.joe.Quantitydisc3.checked)
{NewCount = NewCount + 1}

if (document.joe.Quantitydisc4.checked)
{NewCount = NewCount + 1}

if (document.joe.Quantitydisc5.checked)
{NewCount = NewCount + 1}


if (NewCount == 2)
{
alert('Seulement 1 choix')
document.joe; return false; 
}


}