var id = "";
var constTop = 0;
var top = 0;
function drop (id) {	

		this.id = id;
		document.getElementById (id).style.height = document.getElementById (id).offsetHeight;
		top = document.getElementById (id).style.height;
		
		top = top.replace (/px/, "");
		top = parseInt (top);

		constTop = document.getElementById (id+"_table").offsetHeight;
		
		if (document.getElementById (id).style.visibility == "hidden") {
			
			show ();
		}
		else {
		    document.getElementById(id).style.visibility = "hidden";
		    document.getElementById(id).style.position = "absolute";
			hide ();
		}
}
function show() {
		if (top < constTop) {
			top = top+2;
			document.getElementById (id).style.height = top+"px";
			setTimeout ('show()', 0);
		}
		else {
		    document.getElementById(id).style.visibility = "visible";
		    document.getElementById(id).style.position = "relative";
		}
}


function hide() {		
		
		if (top > 0) {
			top = top-2;
			document.getElementById (id).style.height = top+"px";
			setTimeout ('hide()', 0);
		}

}