MATLAB: How to call a function that outputs text files

function

I keep getting this error,
 ??? Error using ==> SECTOR
Too many output arguments.
for a function I created that outputs text files
The purpose of the function is that when the user types a corresponding number, MATLAB opens a file (fopen) which has been taken from a urlwrite function.
I am proceding the following way
 function fid = SECTOR(user_entry1)
 %

 %
 urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz722.txt','Anegada_Passage_Southward.txt'); % URL from forecast webpage
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz710.txt','Atlantic_Waters.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz732.txt','Caribbean_Waters.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz715.txt','Coastal_Waters_Northern_Culebra_NOT_EasternPR.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz742.txt','Coastal_Waters_Northwestern.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz725.txt','Coastal_Waters_Southern.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz745.txt','Coastal_Waters_Southwestern.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz741.txt','Mona_Passage_Southward.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz712.txt','Coastal_Waters_Northern.txt');
  urlwrite('http://weather.noaa.gov/cgi-bin/fmtbltn.pl?file=forecasts/marine/coastal/am/amz725.txt','Coastal_Waters_Southern_Vieques_Eastern.txt');
if user_entry1 == 1
fid=fopen('Anegada_Passage_Southward.txt');
 elseif user_entry1 == 2
    fid=fopen('Atlantic_Waters.txt');
elseif user_entry1 == 3
    fid=fopen('Caribbean_Waters.txt');
elseif user_entry1 == 4
    fid=fopen('Coastal_Waters_Northern_Culebra_NOT_EasternPR.txt');
elseif user_entry1 == 5
    fid=fopen('Coastal_Waters_Northwestern.txt');
elseif user_entry1 == 6
    fid=fopen('Coastal_Waters_Southern.txt');
elseif user_entry1 == 7
    fid=fopen('Coastal_Waters_Southwestern.txt');
elseif user_entry1 == 8
    fid=fopen('Mona_Passage_Southward.txt');
elseif user_entry1 == 9
    fid=fopen('Coastal_Waters_Northern.txt');
elseif user_entry1 == 10
    fid=fopen('Coastal_Waters_Southern_Vieques_Eastern.txt');
end
and the program file that calls the function goes like this,
 fprintf('Choose your forecast region by typing corresponding number:\n 1. Anegada Passage\n 2. Atlantic Waters\n 3. Caribbean Waters\n 4. Coastal Waters Northern | Culebra\n 5. Coastal Waters Northwestern\n 6. Coastal Waters Southern\n 7. Coastal Waters Southwestern\n 8. Mona Passage Southward\n 9. Coastal Waters Northern\n 10. Coastal Waters Eastern | Vieques\n');
  user_entry1=input('Input forecast: ');
  fid = SECTOR(user_entry1);
The output of the function must be a text file that later would go as an input in the variable 'fid'.
Can you please help?
NOTE: I am trying to format the code starting with 'if user_entry1 == 1…', but MATLAB does not let me.

Best Answer

Add this code before the final end:
else
  warningMessage = sprintf('Error: you entered %d.\nThe allowed values are integers 1 through 10', user_entry1);
  uiwait(warndlg(warningMessage));
  fid = -1;
Then if you enter something not allowed, at least it will warn you.
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