public bool AddCostumer(Costumer c)//adds a Costumer
{
if (!(int.Parse(c.tz) > 0 && (int.Parse(c.tz) < 1000000000)))
{
throw new Exception("costumer name numst be a string...try again please");
}
if (c.costumerAge < 18)
{
throw new Exception("costumer age under 18...try again please");
}
return(dal.AddCostumer(c));
}
