Assuming 'S' is a structure with the given fieldnames and values, you can loop through the structure and create the required string (maybe, using sprintf), which can then be displayed in a message box using 'msgbox' function of MATLAB.
For example,
fields = fieldnames(S); %get the field names
for i=1:length(fields)
fieldName = fields{i};
fieldValue = S.(fieldName);
%str = create the required string with the extracted fieldName and fieldValue
...
end
% at this point, 'str' contains the whole string
msgbox(str)
Hope this helps.
Thanks!