function SetTabsRowPosition(obj) {
    // get the max offset of two tabs row
    var tabsRow1 = document.getElementById("tabsRow1");
    var tabsRow2 = document.getElementById("tabsRow2");

    var offsetTopRow1 = tabsRow1.offsetTop;
    var offsetTopRow2 = tabsRow2.offsetTop;

    var maxOffset = (offsetTopRow1 > offsetTopRow2) ? offsetTopRow1 : offsetTopRow2;

    var firstRow = (offsetTopRow1 > offsetTopRow2) ? tabsRow2 : tabsRow1;
    var secondRow = (offsetTopRow1 > offsetTopRow2) ? tabsRow1 : tabsRow2;

    // if selected tab is not in the second row, exchange the postion of tab rows 
    var tabrowid = obj.parentNode.parentNode.id;
    if (tabrowid != secondRow.id) {
        if (tabrowid == "tabsRow1") {
            firstRow.style.top = maxOffset + "px";
            secondRow.style.top = -maxOffset + "px";
        }
        else {
            firstRow.style.top = "0px";
            secondRow.style.top = "0px";
        }

    }

}