var Timeout = 15000;
var Divs = new Array();
Divs[0] = "bottom-col-three";
Divs[1] = "bottom-col-threeb";
var DivCount = 2;
var currentDiv = 0;

function startCycle() {
    var Div = document.getElementById(Divs[currentDiv]);
    if (Div) {
        $("#" + Divs[currentDiv]).hide();
        /*Div.style.display = "none";*/
        currentDiv = (currentDiv + 1) % DivCount;
        Div = document.getElementById(Divs[currentDiv]);
        if (Div) {
            $("#" + Divs[currentDiv]).show();
            /*Div.style.display = "";*/
        }
    }
    setTimeout("startCycle()", Timeout);
}

startCycle();