how to know that the data is passed between dal,bal and presentation layer

HI ALL,

I HAVE A "PRESENTATION LAYER" IN WHICH IAM PASSING A "INTEGER VALUE" IN TEXTBOX
I HAVE A "BUSINESS LAYER" THROUGH WHICH IAM PASSING THE "INTEGER TO DAL"
IN DAL IAM USING WCF CREATED SERVICE AND GETTING THE VALUE AND DISPLAYING IT
public interface IService1
{

[OperationContract]
string GetData(int value);

[OperationContract]
CompositeType GetDataUsingDataContract(CompositeType composite);

// TODO: Add your service operations here
}

public class Service1 : IService1
{
public string GetData(int value)
{

return string.Format("You entered: {0}", value);

}
problem:
IAM RUNNING THE APPLICATION BUT NO ERROR OR OUTPUT COMES,THE ASPX PAGE LOADS FINE

gogul