var myimages = new Array();
function preloading(){
	for (x=0; x<preloading.arguments.length; x++){
		myimages[x] = new Image();
		myimages[x].src = preloading.arguments[x];
	}
}

preloading(
	"images/nav/login_hover.gif",
	"images/nav/start_hover.gif",
	"images/nav/align_hover.gif",
	"images/nav/connect_hover.gif",
	"images/nav/optimize_hover.gif"
);

function clearInputField(elem) {
    var txt = document.getElementById(elem);
    txt.value = "";
}
// reference: http://www.htmlite.com/JS020.php