STOCKHOLM (Reuters) - Swedish police must wish all criminals were as naive as the Halmstad robber. The 47-year-old man walked into the post office of the small town in southern Sweden, told the cashier he was armed and demanded a bag of cash -- plus 350 million crowns (23 million pounds) to be paid into his bank account, whose number he handed her on a piece of paper. Police had no trouble tracking him down and made a speedy arrest, the Swedish news agency TT reported Monday.