function questionary_totle()
{
var rows = document.getElementsByTagName('tr');
for (var i=0;i<rows.length;i++){
	rows[i].onmouseover = function(){		//鼠标在行上面的时候
		this.className += 'altrow';
	}
	rows[i].onmouseout = function(){		//鼠标离开时
		this.className = this.className.replace('altrow','');
	}
}
}