function check(){
if (document.loginform.nickname.value == "")
		{
		alert("请输入用户名");
		document.loginform.nickname.focus();
		return false;
		}
if (document.loginform.password.value == "")
		{
		alert("请输入密码");
		document.loginform.password.focus();
		return false;
		}
   return true
 }

function show_sader(mylink)
{
  window.open(mylink,'','top=140,left=135,width=480,height=110,scrollbars=no')
}