function jiancha(myform)
{
	var name2,pwd2;
	name2=myform.username.value;
	pwd2=myform.passwd.value;
	if (name2=="" || pwd2=="")
		{
		alert("用户名或密码不能为空");
		myform.username.focus();
		return false;
		}
	else		
	return true;
}