function water_in(fieldid,class_name){
	var obj=document.getElementById(fieldid);
     obj.className=class_name;

}
function water_out(fieldid,class_name,class_clear){
	var obj=document.getElementById(fieldid);
	if(obj.value=="") {
		obj.className=class_name;
	}else{
		obj.className=class_clear;
	}
}