Functions

    /*
    To keep your code tidy you can put code pieces
    together in a function. You can use them more than one time.
    Like this
    */

    main();
    
    // the main code
    function main () {   
    var a_string = "Uh. I really want to know how many characters are in me!";
    var res = calc_str_length (a_string);
    alert(res);
    var b_string = "lets see how many characters I have!";
    res = calc_str_length (b_string);
    alert(res);
    // you don't need this return thing here
    // but it is cleaner that way
    // also have a look at the ESTK console
    return 0;
    }

    // the calc function
    function calc_str_length(str){
    var l = str.length;
    return l;
    }