function calculate_costofmembership()
{

if (IsNumeric(document.getElementById("app_ftemployees").value) == true)
{
document.getElementById("app_membershipcost").value = 365 + 25 + (document.getElementById("app_ftemployees").value*6)
}
else
{
document.getElementById("app_membershipcost").value = ""
document.getElementById("app_ftemployees").value = ""
alert("Please insert a valid numeric value")
}

}

function IsNumeric(sText)
{
   var ValidChars = "0123456789";
   var IsNumber=true;
   var Char;

 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
}
   return IsNumber;
}

function popUp(URL) {
day = new Date();
id = day.getTime();
eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=1,menubar=0,resizable=0,width=400,height=346,left = 760,top = 427,bgcolor=#000000');");
}