Create 3 new fields in your query. The first one checks the value of textbox1 and ignores it if it is null. In the FIELD box of the query, type:
IIF(isnull([Forms]![frmDataSearch]![textbox1]),-1,[strname] Like *&[Forms]![frmDataSearch]![textbox1]&*
When you hit ENTER, Access will place a...