function visibility(divID){
	 var item = document.getElementById(divID);
	 if(item){
		 item.className=(item.className=='hidden')?'unhidden':'hidden';
	 }
}
function show(){
	visibility('filldiv');
	visibility('registerdiv');
}
function clearText(field){
    if (field.defaultValue == field.value) field.value = '';
    else if (field.value == '') field.value = field.defaultValue;
}