Expanding 1D array using for loop

I have the code below. What I am trying to do is accept/store an arbitrary number of positive input values (into the "values" array) using a for loop. I do not have a pre-determined amount of positive numbers, that I am going to accept, rather the goal is for the user to keep entering numbers (as prompted) until he/she enters a non-positive number. I think the crux of the problem lies with dynamically expanding the values array.

Any suggestions?

i=1;
n=input('Enter initial value: '); 
values(i)=n;

for i=1:length(values)
  if n>0;
    n=input('Enter next value: ');
    i=i+1;
  else
    disp('ERROR: All numbers entered must be positive!');
    break;
  end
end

Answer 1

[Star Strider]

This seems to work:

n = 1;
i = 0;

n=inputdlg('Enter initial value: ');
n = str2num(cell2mat(n));
while n>0;
    i=i+1;
    values(i) = n;
    n=inputdlg('Enter next value: ');
    n = str2num(cell2mat(n));
end
msgbox('ERROR: All numbers entered must be positive!');

I used the inputdlg and msgbox functions because they keep the Command Window from getting cluttered.