coordinate transformation - geographic to projected (utm)

Hello,

I was trying to project geographic (lat lon, in degrees) to projected system (utm, meters). I have a text file that has the lat and lon in degree. I am using another function to read the lat and lon from the text file called ReadlatLon.m. When I am using the code below, its returning the following error massage. Index exceeds matrix dimensions

Error in deg2utm (line 65) la=lat(i);

The code is as follows:

function  [lat_utm,lon_utm,utmzone] = deg2utm(lat,lon)
[lat,lon] = ReadLatLon('latlon.txt');

%the latlon.txt is in the following format
% Npoints
% LAT LON
% LAT LON
% LAT LON
% .    .

npts = length(lat);

lat_utm=zeros(npts,1);
lon_utm=zeros(npts,1);
utmzone(npts,:)='60 X';

for i=1:npts
   la=lat(i);
   lo=lon(i);

     sa = 6378137.000000 ; sb = 6356752.314245;

     %e = ( ( ( sa ^ 2 ) - ( sb ^ 2 ) ) ^ 0.5 ) / sa;
     e2 = ( ( ( sa ^ 2 ) - ( sb ^ 2 ) ) ^ 0.5 ) / sb;
     e2cuadrada = e2 ^ 2;
     c = ( sa ^ 2 ) / sb;
     %alpha = ( sa - sb ) / sa;             %f
     %ablandamiento = 1 / alpha;   % 1/f

     lat = la * ( pi / 180 );
     lon = lo * ( pi / 180 );

     Huso = fix( ( lo / 6 ) + 31);
     S = ( ( Huso * 6 ) - 183 );
     deltaS = lon - ( S * ( pi / 180 ) );

     if (la<-72), Letra='C';
     elseif (la<-64), Letra='D';
     elseif (la<-56), Letra='E';
     elseif (la<-48), Letra='F';
     elseif (la<-40), Letra='G';
     elseif (la<-32), Letra='H';
     elseif (la<-24), Letra='J';
     elseif (la<-16), Letra='K';
     elseif (la<-8), Letra='L';
     elseif (la<0), Letra='M';
     elseif (la<8), Letra='N';
     elseif (la<16), Letra='P';
     elseif (la<24), Letra='Q';
     elseif (la<32), Letra='R';
     elseif (la<40), Letra='S';
     elseif (la<48), Letra='T';
     elseif (la<56), Letra='U';
     elseif (la<64), Letra='V';
     elseif (la<72), Letra='W';
     else Letra='X';
     end

     a = cos(lat) * sin(deltaS);
     epsilon = 0.5 * log( ( 1 +  a) / ( 1 - a ) );
     nu = atan( tan(lat) / cos(deltaS) ) - lat;
     v = ( c / ( ( 1 + ( e2cuadrada * ( cos(lat) ) ^ 2 ) ) ) ^ 0.5 ) * 0.9996;
     ta = ( e2cuadrada / 2 ) * epsilon ^ 2 * ( cos(lat) ) ^ 2;
     a1 = sin( 2 * lat );
     a2 = a1 * ( cos(lat) ) ^ 2;
     j2 = lat + ( a1 / 2 );
     j4 = ( ( 3 * j2 ) + a2 ) / 4;
     j6 = ( ( 5 * j4 ) + ( a2 * ( cos(lat) ) ^ 2) ) / 3;
     alfa = ( 3 / 4 ) * e2cuadrada;
     beta = ( 5 / 3 ) * alfa ^ 2;
     gama = ( 35 / 27 ) * alfa ^ 3;
     Bm = 0.9996 * c * ( lat - alfa * j2 + beta * j4 - gama * j6 );
     xx = epsilon * v * ( 1 + ( ta / 3 ) ) + 500000;
     yy = nu * v * ( 1 + ta ) + Bm;

     if (yy<0)
         yy=9999999+yy;
     end

     lat_utm(i)=xx;
     lon_utm(i)=yy;
     utmzone(i,:)=sprintf('%02d %c',Huso,Letra);
  end