Sorry forget to point you a reply i made on autocomplete textbox there is some days.
verify also if the table Home(7)+"autocomp.dbf" satnds here.
i duplicate it below:

Publi yform
yform=Createobject("yauto")
yform.Show
Read Events
Retu
*
Define Class yauto As Form
	BorderStyle = 0
	Height = 367
	Width = 571
	AutoCenter = .T.
	Caption = "Form1"
	MaxButton = .F.
	Name = "Form1"

	Add Object text1 As TextBox With ;
		FontSize = 11, ;
		Height = 37, ;
		Left = 48, ;
		SelectOnEntry = .T., ;
		Top = 18, ;
		Width = 204, ;
		AutoComplete = 1, ;
		Name = "Text1"

	Add Object edit1 As EditBox With ;
		FontName = "Comic Sans MS", ;
		Height = 302, ;
		Left = 8, ;
		ReadOnly = .T., ;
		ScrollBars = 0, ;
		Top = 62, ;
		Width = 552, ;
		Name = "Edit1"

	Add Object command1 As CommandButton With ;
		Top = 18, ;
		Left = 420, ;
		Height = 25, ;
		Width = 121, ;
		Caption = "Clear Hystory", ;
		Name = "Command1"


	Procedure Destroy
	Clea Events
	Endproc

	Procedure text1.GotFocus
	Keyboard "{CTRL+A}"
	Endproc

	Procedure edit1.Init
	TEXT to this.value noshow
		Help:
		Set the AutoComplete property to provide a text box that automatically stores
		and suggests values. As characters are typed, a drop-down list displays recently
		entered words that match the pattern of the typed characters. When the
		user selects an entry from the list, the text box value becomes equal
		to that entry and updates the usage information for that entry in the
		Autocomp.dbf or other table you have specified.

		The autocomplete textbox gathers a great quantity of informations.can reset it by
		this simple trick.(of course its a table located in home(7))

		use home(7)+"autocomp.dbf"
		zap  &&Removes all records from a table, leaving just the table structure.
		use in home(7)+"autocomp.dbf"
		this remove all autocomp historical data.
		can also appe your personal table (same structure as autocomp.dbf) to autocomplete.dbf
		and work with.
	ENDTEXT
	Endproc

	Procedure command1.Click
	Close Data All
	Use Home(7)+"autocomp.dbf" Alias yautocomp
	Select yautocomp
	Brow
	If Messagebox("Want to zap all hystory data ?",4+64+4096,"Autocomplete.dbf")=6
		Zap
	Endi
	Use In Select("yautocomp")
	Endproc

Enddefine
*
*-- EndDefine:yauto