How to send custom object from client to server ?

How to send custom  object from client to server ?

if i have a class task at client side and i need to send List of task to server. How to do this.

I have saved the data in local database in the WP7 . I have a Task table there . There may be 10,15,20 or... rows of data in that table . I want to send those number of rows of data to server using my wcf service . I am able to send the parameter to the server like i have a login method in the wcf which takes email and password as parameter returns boolean value true or false. Now I need to send these few 10,15,20 or... rows of data to the server via the WCF service and save in the server database. I am stuck at sending the number of rows to the wcf method. I have the Task data in list object. I have debugged and checked the presence of data.

Here is the code part

using(dbContext context =new dbContext()){IQueryable<tasks> taskStatQuery =from t in context.Tasksselect t;List<tasks> allTasksStatus = taskStatQuery.ToList();WcfFSMSer.Win7MobileServiceClient client =newWcfFSMSer.Win7MobileServiceClient();       client.TestFunctionAsync(whatParamToSendForSendingFewRows);      client.TestFunctionCompleted+=newEventHandler<WcfFSMSer.TestFunctionCompletedEventArgs>(client_TestFunctionCompleted);}void client_TestFunctionCompleted(object sender,WcfFSMSer.TestFunctionCompletedEventArgs e){}

I am able to get all tasks list in this variable List allTasksStatus.

How to send these values from WP7 to WCF?

Thanks in advance