Prompt User For Confirmation Before Running Macro

I am using VBA to create a weightloss calculator and everything is going fine ecept the Vbyesno boolean that will not allow me to delete the data that i want.

I used a macro to delete the information that i want to delete and i know it works because without the vbyesno, it works fine.

With the vbyes no, both yes and no do nothing when clicked and the yes no box just closes.

The macro code is stored in a private sub called "ClearAll"

My code is:

Private Sub Restart_Click()
Dim Response As Boolean
Response = MsgBox ("Are you sure",YbYesNo)
If Response = VbYes Then
Call ClearAll
End If
End Sub

What am i doing wrong?

I also want to make the no button the default, how do i do this in conjunction with the code above?