function geto(i) {
	if(document.getElementById) return(document.getElementById(i));
	else if(document.all) return(document.all[i]);
	else if(document.layers) return(document.layers[i]);
	else return null;
}
function field_focus(f) {
	geto(f).className = "focus";
}
function field_blur(f) {
	var o;
	if((o = geto(f)).value.length == 0)
		o.className = "blur";
}