function CalculateTotalCost()
{
 var cost = 0;
 //get attending type
 if (document.getElementById("rbSinglePayment").checked == true)
 {
    cost = cost + 25
 }
 else
 {
    if (document.getElementById("rbCouplePayment").checked == true)
    {
        cost = cost + 40
    }
    else
    {
        var PartyCount = Number(document.getElementById("txtPersonCount").value)
        cost = cost + (PartyCount * 25)
    }
 }
 
 //get number of youth
 cost = cost + (Number(document.getElementById("txtYouthCount").value) * 15)
 
 //get lunch numbers
 cost = cost + (Number(document.getElementById("txtLunch").value) * 20)
 //Display results
 document.getElementById("lblTotalCost").innerHTML = "$ " + String(cost) + ".00"
}