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);
	}
}