Add controls/fields when pressing “enter”

I need to add an additional row of specific fields/controls (text box, combo box) mimicking the previous when the user presses “enter” after typing in the last text box on that row.

Basically, the data input fields need to be able to grow sequentially without

cluttering up the form with unneeded rows of fields. Can somebody help me with either the XML or C# calls for accomplishing this?

Thank You!