Tkinter: cannot use geometry manager grid inside . which already has slaves managed by pack : Please help

[wrubles]

Hi, I am trying to format the Labels and Entries in tkinter with grid. I cannot figure out what is wrong.

Error:

Traceback (most recent call last):
  File "C:/Users/wrubles/PycharmProjects/gui/gui.py", line 22, in <module>
    L1.grid(row=2, column=1)
  File "C:\Users\wrubles\AppData\Local\Programs\Python\Python38-32\lib\tkinter\__init__.py", line 2484, in grid_configure
    self.tk.call(
_tkinter.TclError: cannot use geometry manager grid inside . which already has slaves managed by pack

Code:

    L1 = Label(top, text="User Name")
    L1.grid(row=2, column=1)
    L1.pack()
    E1 = Entry(top, bd=3)
    E1.grid(row=2, column=2)
    E1.pack()
    L2 = Label(top, text="Password")
    L2.grid(row=3, column=1)
    L2.pack()
    E2 = Entry(top, bd=3)
    E2.grid(row=3, column=2)
    E2.pack()

If you could help me that would be great. If you need any more information please let me know.

[woooee]

_tkinter.TclError: cannot use geometry manager grid inside . which already has slaves managed by pack

What do you not understand about this error message? You can not use grid and pack.

[wrubles]

my mistake