Prevent Text Box Loosing Focus

I want to type some data into a text box on a form, after I press enter I want to do sothing with the data (add it to a list box, no problem) and then go back to the textbox for another entry.

Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
Call processdata
End Sub

Sub processdata()

A = TextBox1.Value
' Do something with A
TextBox1 = ""
TextBox1.SetFocus

End Sub

I can do somthing with the data but it does not jump back to the Textbox i.e. the setfocus does not work.