Guide NaN problem for user inputs to the uitable

I have a table and I use an 'add row' button to append new rows when necessary. I have 6 columns and the first column is ought to be Name. I want the user to be able to edit the first row and write on it. However, when a letter is written it becomes 'NaN'.

The code to add the row is:

data = get(handles.uitable1, 'Data');
data(end+1,:) = [0 0 0 0 0 0];

First zero should be displayed as 'Name' and should be editable.