sub card_choice {
    if ($cardspeed eq "fast") {
	$cardusagemenu->AddItems([
				   "radiobutton"=>"1M Sample Full Channel 600MHz Conventional",
				   "-value"=>"1M Sample Full Channel 600MHz Conventional",
				   "-variable"=>\$cardusagechoice  
				   ],
				  [
				   "radiobutton"=>"2M Sample Half Channel 1.2GHz Conventional",
				   "-value"=>"2M Sample Half Channel 1.2GHz Conventional",
				   "-variable"=>\$cardusagechoice
				   ],
				  [
				   "radiobutton"=>"1M Sample Full Channel 600MHz Transitional",
				   "-value"=>"1M Sample Full Channel 600MHz Transitional",
				   "-variable"=>\$cardusagechoice
				   ]);
    }
    elsif ($cardspeed eq "slow") {
	$cardusagemenu->AddItems([
				   "radiobutton"=>"2M Sample Full Channel 333MHz Conventional",
				   "-value"=>"2M Sample Full Channel 333MHz Conventional",
				   "-variable"=>\$cardusagechoice  
				   ],
				  [
				   "radiobutton"=>"4M Sample Half Channel 666MHz Conventional",
				   "-value"=>"4M Sample Half Channel 666MHz Conventional",
				   "-variable"=>\$cardusagechoice
				   ],
				  [
				   "radiobutton"=>"2M Sample Full Channel 333MHz Transitional",
				   "-value"=>"2M Sample Full Channel 333MHz Transitional",
				   "-variable"=>\$cardusagechoice
				   ]);
    }
}