Move repetive lines of code into a for loop

Question

I want to move the 12 lines of code into a for loop. However it is not working. Working code without for loop

createCalendar(calendar1, varYear, 1);
createCalendar(calendar2, varYear, 2);
createCalendar(calendar3, varYear, 3);
createCalendar(calendar4, varYear, 4);
createCalendar(calendar5, varYear, 5);
createCalendar(calendar6, varYear, 6);
createCalendar(calendar7, varYear, 7);
createCalendar(calendar8, varYear, 8);
createCalendar(calendar9, varYear, 9);
createCalendar(calendar10, varYear, 10);
createCalendar(calendar11, varYear, 11);
createCalendar(calendar12, varYear, 12);

I tried this with no luck

    var i;
    var txt;
 
    for (i=1; i<=12; i++){
      txt = 'calendar' + i
      createCalendar(txt, varYear, i);
    }