Auto Populate a Form Text Box?

Hi,
Don't know if this is possible but want to give it a shot. So i have a form that is filled out with a Name, Date, Amount, and a Code. When you press submit it puts the data in columns A, B, C, & D. And continues to do the same on the next row as you enter more of the same data. So the question is, am I able to have the form pre-populate a name or code that has already been used? Example would be how excel gives you the rest of a name if you enter the first letter after its already been used once before. I wanted to see if this could be used in the form I created? Any thoughts?
Here is the code I have for my Submit Button on the form:

Private Sub CommandButton1_Click()

Columns("A").End(xlDown).Select

ActiveCell.Offset(1, 0).Value = TextBox1.Text

ActiveCell.Offset(1, 1).Value = TextBox2.Text

ActiveCell.Offset(1, 2).Value = TextBox3.Text

ActiveCell.Offset(1, 3).Value = TextBox4.Text

Unload UserForm1
UserForm1.Show


End Sub

Thanks So Much!
Jason

Hey Marvin,
Thanks for the response. If I use a ComboBox instead of a TextBox wont I only be able to have the name field restricted to the names I have it pointed to like a list? Or will it auto populate the ComboBox after the data is submitted. My concern is that this excel sheet is used to break down data and is then deleted and new data for new names is entered so there wont be specific names or codes used over and over.. does that make sense? Sorry if this is confusing..