//preload image

var collimg = new Image();

collimg.src = "../images/log_in_buttonoff.gif";

var expimg = new Image();

collimg.src = "../images/log_in_button.gif";



function ShowHideLayer(boxID) {

	/* Obtain reference for the selected boxID layer and its button */

	var box = document.getElementById("box"+boxID);

	var boxbtn = document.getElementById("btn"+boxID);

	

	/* If the selected box is currently invisible, show it */

	if(box.style.display == "none" || box.style.display=="") {

		box.style.display = "block";

 		boxbtn.src = "images/log_in_buttonoff.gif";

	}

	/* otherwise hide it */

	else {

		box.style.display = "none";

		boxbtn.src = "images/log_in_button.gif";

	}

}