Macro relative references

I'm attempting create a macro that will add a new line below the line in which the user is, copies all data and formulas from the line above, except for columns G and H. Ends in Column G, ready for editing. I came up the macro below, which does what I want, if you are in row 3, but how do I generalize it.

Another way to ask the question, how do I change the reference
Rows("4:4").Select
to something that means select the row below the one I'm in. e.g.
Rows("the-one-I'm-in+1").Select

Sub AddSecondProduct()
'
' AddSecondProduct Macro

'
    Rows("4:4").Select
    Selection.Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
    Rows("3:3").Select
    Selection.Copy
    Rows("4:4").Select
    ActiveSheet.Paste
    Range("G4:H4").Select
    Application.CutCopyMode = False
    Selection.ClearContents
    Range("G4").Select
End Sub

Any help appreciated.
JensPeter