Question

When I try to run this program, I get an error in Firefox saying that:

moveDate is undefined on line 41

(referring to the line window.setTimeout("moveDate()",100);.

Any ideas why? I thought recursive functions were able to define themselves and then call upon themselves.

function monthScroller(){
    document.getElementById("month").style.visibility = "visible";
    var x = 0;
    var y = 0;
    var dest_x = window.innerWidth/2;
    var dest_y = window.innerHeight/2;  
    var interval = 1;

    function moveDate() {
        if(x<dest_x){ x = x + interval;} 
        if(y<dest_y){ y = y + interval;}

        document.getElementById("month").style.top  = y+"px";
        document.getElementById("month").style.left = x+"px";

        if ((x+interval < dest_x) && (y+interval < dest_y)) {
                window.setTimeout("moveDate()",100);
        }
        else{
            name();
        }
    }
    moveDate();
}

Answer 1

Yes, they are. Yet, window.setTimeout("moveDate()",100); will eval that code string in the global scope – no moveDate to be found there. Instead, pass the function reference to setTimout():

 window.setTimeout(moveDate, 100);