function checkbox_click(object,check_id){
	if(object.className=='checkbox' || object.className=='checkbox_over'){
		object.className='checkbox_on'; 
		document.getElementById(check_id).value='on';
	}else{
		object.className='checkbox'; 
		document.getElementById(check_id).value='';
	}
}
function checkbox_over(object){
	if(object.className=='checkbox')
		object.className='checkbox_over';
}
function checkbox_out(object){
	if(object.className=='checkbox_over')
	object.className="checkbox";
}