Post to wcf service windows phone 7

namespace sendsms
{
public partial class Page1 : PhoneApplicationPage
{
public Page1(string s , string u , string t)
{
InitializeComponent();
smssendClient client = new smssendClient();
client.sendsmsCompleted += new EventHandler(client_sendsmsCompleted);
client.sendsmsAsync(s, u, t);

}
void client_sendsmsCompleted(object sender, sendsmsCompletedEventArgs e)
{
textBlock1.Text = e.Result;
}
}
}