Simulate Enter Press To Close Message Box?

I have a password form that contains a load of buttons. The user has to enter a four digit, numeric, password to procede. They do this by pressing one of 10 number buttons on the screen, the keyboard isn't used. If they enter the wrong password an error message pops up (this isn't using the error tool I just added a message box msgbox("Error Code #638492") or something) if the user doesn't enter a password, after 5 seconds (I use a timer called Timer1 with an interval of 5 seconds) the form closes and it goes back to the previous page.

My only problem is when I close the form using Me.close(), the message box is still displayed. And if the message box is still displayed it doesn't work. The form is miminized (I have the application in full screen) so this is very bad. What I need is to simulate the enter key press then close the form so the enter key is pressed, the messagebox close then the password form closes.I can do this using SendKeys.Send("{ENTER}"). Here's the sub I use:

[code]...

However, if I don't have the 'Close()' line of code in the message box closes as it should. If I don't have the message box open and I don't use the SendKeys.Send("{ENTER}") then the close() line works perfectly and close the password form as it should?