Adding the column as street name2 in Address tab of custtable ,the combination of streetname & street name2 i will be displayed in address grid how to do that

Hi ....this is suma

        i can  add a column   in the address tab of Customer form. Column name  as street name2  in the address tab ,i want the address i.e combition of street name and street name 2 exhibited  into  the bottom of Address grid of customer form. how to do that,  can any one solve this.....if anyone unclear about this could u plz inform to me..