Userform Won't Load Info From Database Sheet To Invoice Sheet

I have a list box that I'm using to pull customer information from my "Customer" sheet to my "Invoice" sheet. I can actually open, select, and close the userform. However, I can't get the macro to put the information into the specified location on my "Invoice" sheet.

Here's my code so far:

Private Sub Cancel_Click()
Application.ScreenUpdating = False

Unload Me

End Sub

Private Sub customer_Change()

End Sub

Here is the "Customer" sheet I'm pulling the info from:

And here is the location on the "Invoice" sheet that I'm trying to direct the userform to:

And here's my userform just for reference:

The userform works perfectly until I press the OK button. That's when I get the error.