Hi, I'm having problems with my find button

Private Sub Btnfind_Click(ByVal sender As System.Object, ByVal _
e As System.EventArgs) Handles Btnfind.Click
MainFormTableAdapter.FillByLastName(_6776_BDataSet.MainForm, Txtfind.Text)

I get the error:Too many arguments to 'Public Overridable Overloads Function FillByLastName(dataTable As _6776_BDataSet.MainFormDataTable) As Integer'.

I'm trying to create a find button which allows the user to bring up a customers record after entering thier last name.