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);
        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;
}

function toggleSlide(objname){
  if(document.getElementById(objname).style.display == "none"){
    // div is hidden, so let's slide down
    slidedown(objname);
 }
 else{
    // div is not hidden, so slide up
    slideup(objname);
	}
}

function nav(objname){
var f=1
for (f=1;f<=30;f++)
{
slideup("nav" + f);
slidedown(objname);
}
}

function art(objname){
var f=1
for (f=1;f<=30;f++)
{
slideup("art" + f);
slidedown(objname);
}
}