Applying If in macro to range of data

How would I apply this to an entire range of data? I want all of the columns to stay the same, I just want this to autmatically fill in from row 2 to the end of my range of data.

    If Range("H2") = "" Then
    Range("J2") = Range("I2")
    Else
    Range("J2") = Range("H2") & " " & Range("I2")
    End If

Thanks.