[R] a new df with one combined column

[chalabi.elahe at yahoo.de]

Hi all,
I have this column as a part of df:
 
    $License :   Factor W/384 levels "41005","41006","41034","41097","41200",...
and I have other column which is a part of other df lets say df2:

    $Diff    :   int  41166 41202 41290 41353 41503 41507 41548
these two columns df$License and df$Diff have different dimensions and I want to make a new df that is combinations of both i.e. I want a column which has both of these columns together as one column, but I don't know how to bring these two column in one as a new df. Does anyone know how should I do that?
Thanks for any help,
Elahe