//works
public List <int> getAvailableTrucks()
{
List <int> truckNumbers = new List <int>();
if (System.Threading.Monitor.TryEnter(obj6, 45000))
{
try
{
truckNumbers = truckCtr.getAvailableTrucks();
}
finally
{
System.Threading.Monitor.Exit(obj6);
}
}
return(truckNumbers);
}