PowerApps Login screen issue

Question

I have created PowerApps Canvas app name as Login screen.

 

There i have created a SP list FOr users credential fields are (Username & Password)

 

canvas powerApp their is two screen: login and welcome screen.

 

Login screen :

1  Label for tiltle - lbltitle

2. Label for UserName - lblUserName

3. Label for UserPassword - lblUserPassword

4. input text for UserName-  txtUserName

5. input text for UserPassword- txtUserPassword

6. Button - Button1 (in screen name is 'Login')

 

Welcome screen:

 Label for title - lblDisplayMsg

 

selected "OnSelect" i have wrote formula which is not working

 

If(CountRows(Filter('User Credential',And(txtUserName.Text = UserName,

txtUserPassword.Text = UserPassword)))=Button1,Navigate('Welcome Screen',None),Notify("Invalid Login Details",

Error));Reset(txtUserName);Reset(txtUserPassword);

 

When i am entering UserName & Password and click on Login button not redirecting to Welcome screen. need help.

 

Thanks