wpf navigate from page to window

Question

Hello my name is Badr and I am a newbie and now I am building a project using WPF. My problem is that I want to hide / close the window when moving from page to another window.

i tried this

 

win_Main win_main = new win_Main();

win_main.ShowDialog();

win_Login win_login=new win_Login();

win_login.close();

 

and this also :

 

this.close();

 

it's not working