function pressEngine(new_engine, old_engine) {
	var new_idbtn_top = 'top_btn_'+new_engine;
	var new_btn_top = getObject(new_idbtn_top);
	
	new_btn_top.style.background = 'url(templates/images/BTN_'+new_engine+'_press.gif) no-repeat center';
	
	var old_idbtn_top = 'top_btn_'+old_engine;
	var old_btn_top = getObject(old_idbtn_top);
	
	if (old_btn_top){
		old_btn_top.style.background = 'url(templates/images/BTN_'+old_engine+'_normal.gif) no-repeat center';
	}
}
function isBtnActive(btn){
	var reg = new RegExp(/(.*?)(press)(.*?)/);
	var str = btn.style.background;
	return str.match(reg);
}