if (select count(*) from sys.syscolumns where tname='Proform' and cname='DDSBankKod')=0
  then
    alter table Proform add DDSBankKod varchar(11)
end if;

GO

if (select count(*) from sys.syscolumns where tname='Invoices' and cname='DDSBankKod')=0
  then
    alter table Invoices add DDSBankKod varchar(11)
end if;

GO

if (select count(*) from sys.syscolumns where tname='SpaInvoices' and cname='DDSBankKod')=0
  then
    alter table SpaInvoices add DDSBankKod varchar(11)
end if;

GO

if (select count(*) from sys.syscolumns where tname='Contracts' and cname='ContrDDSBankKod')=0
  then
    alter table Contracts add ContrDDSBankKod varchar(11)
end if;