how to navigate from one WPF form to another?????

hi,

i created a project in c# and added the wpf windows in the expression blend 4. After adding these windows what all that i can see in the solution explorer are the Window_name.xaml files. now i have created a button in the MainWindow.xaml window, now i want to navigate form this WPF window to the another WPF window named as Window2.xaml on the button click.

can any one suggest me the possible code in c# ??????