How to get value from a cell of a table with Jquery?

How to get value from a cell of a table with Jquery?

Hello, what I need to know is how to get the value from the cells of a html table, for example I have the following table
   
1 12
12 20  

Now I need to retrieve the value of the position(1,2)=12

Better, what I need is to retrieve all the values with cycles, something like
 
for (var i=0;i<($('#tabl tr').length;i++) {
  for (var j=0;j<($('#tabl td').length);j++) {
 var texto = [[row[i].sectionRowIndex, cell[j].cellIndex, $(this).find("option:selected").text()]];//this doesn't work
            alert(texto);
         }
       }