I am trying to create a gui without using guide. I have 2 tables and 2 push buttons on my gui panel. 1 table has fix number of row and column. However, number of column for the other table will change with user input(row is fixed to 6). Based on the data in the tables, I will do some calculation whenever user press the "calculate" push button. Problem starts with calculate push button. I got "Undefined function or variable 't'." error, whenever I want to get the data from tables.( t is name of the one table) . I attached my .m file.