using function sumif to populate values into textbox based on selected combobox

the list of names in column F were all mis-spelt! and SUMIF was incorrect

Private Sub UserForm_Initialize()
    Set Rng = sheet1.Range("f2", sheet1.Range("f" & Rows.Count).End(xlUp))
    Me.ComboBox1.RowSource = Rng.Address
End Sub

Private Sub ComboBox1_Change()
Me.TextBox1.Value = WorksheetFunction.SumIf(Range("B:B"), ComboBox1.Value, Range("C:C"))
Me.TextBox2.Value = WorksheetFunction.SumIf(Range("B:B"), ComboBox1.Value, Range("D:D"))
Me.TextBox3.Value = TextBox1.Value - TextBox2.Value
End Sub