var timerlen = 5;
var slideAniLen = 250;

var timerID = new Array();
var startTime = new Array();
var obj = new Array();
var endHeight = new Array();
var moving = new Array();
var dir = new Array();

function slidedown(objname){
    if (moving[objname])
       return;

    if (document.getElementById(objname).style.display != "none")
        return; // cannot slide down something that is already visible

    moving[objname] = true;
    dir[objname] = "down";
    startslide(objname);
}

function slideup(objname){
    if (moving[objname])
        return;

    if (document.getElementById(objname).style.display == "none")
        return; // cannot slide up something that is already hidden

    moving[objname] = true;
    dir[objname] = "up";
    startslide(objname);
}

function startslide(objname) {
    obj[objname] = document.getElementById(objname);
    
    //endHeight[objname] = parseInt(obj[objname].style.height);
    endHeight[objname] = parseInt($('#site-messages').height());
    startTime[objname] = (new Date()).getTime();

    if (dir[objname] == "down"){
        obj[objname].style.height = "1px";
    }

    obj[objname].style.display = "block";

    timerID[objname] = setInterval('slidetick(\'' + objname + '\');', timerlen);
}

function slidetick(objname){
    var elapsed = (new Date()).getTime() - startTime[objname];

    if (elapsed > slideAniLen)
        endSlide(objname)
    else {
        var d =Math.round(elapsed / slideAniLen * endHeight[objname]);
        if (dir[objname] == "up")
            d = endHeight[objname] - d;

        obj[objname].style.height = d + "px";
    }

    return;
}

function endSlide(objname){
    clearInterval(timerID[objname]);

    if(dir[objname] == "up")
        obj[objname].style.display = "none";

    obj[objname].style.height = endHeight[objname] + "px";

    delete(moving[objname]);
    delete(timerID[objname]);
    delete(startTime[objname]);
    delete(endHeight[objname]);
    delete(obj[objname]);
    delete(dir[objname]);

    return;
}