function nvec=getDriveNumbers(opt,drivenames)

% parses the drivenames, returns numbers

if ~iscell(drivenames)
    drivenames={drivenames};
end
nvec=zeros(length(drivenames),1);

for qq=1:length(drivenames)
    drivename=drivenames{qq};
    if isstr(drivename)
        dotpos=strfind(drivename,'.');
	if length(dotpos)
          n=getDriveIndex(opt, drivename(1:dotpos-1), drivename(dotpos+1:end));
	else
          n=getDriveIndex(opt, drivename);
	end
        if length(n)~=1
            error(['Drivename ',drivename,' unknown']);
            return;
        end
    else
        n=drivename;
    end
    nvec(qq)=n;
end