navigating to second page after validation of username and password in visual studio 2012 windows phone using C#

Hi,

I have created one login form having username and password ,I have restricted username as only number and password as special character ,length greater than 8,(a-z),(A-Z)these all should be there.i have created one LOGIN button ,I want to navigate to second page by clicking login button after validating these two field .

validation for password is not running properly ,I have used code as 

<PasswordBoxx:Name="PasswordBox" 

="PasswordBox_PasswordChanged">

privatevoidPasswordBox_PasswordChanged(objectsender,RoutedEventArgse)

PasswordBoxpassBox = senderasPasswordBox;

boolisValidPassword = passBox.Password.Any(char.IsDigit)

char.IsLetter)

newchar[] { '@','$','#'}) != -1

"valid":"not valid";