passing parameters from To & from mainpage to mvvm

Hi c# corner,

I am using Silverlight Application In that Language is C#.
In that have used WCF enabled Service for accesing Store Procedure from Database.
Even I am using the Mvvm Pattern.but there is no of parameters I am using into Store Procedure and that stored Procedure access in ViewModel  and ViewModel access into my Mainpage.xaml .
but  i need a  Solution that How to pass these parameters of Viewmodel from mainpage.xaml    and Viewmodel to WCF service method   ..

 
please help!!!!!!!!