var newWindow = null
function windowOpener(loadpos)
{       
        if (! newWindow || newWindow.closed)
        {
        newWindow = window.open(loadpos,"surveywin","toolbar,resizable,scrollbars,dependent,width=400,height=280");
        }else
        {
                newWindow.focus();
        }
}

function logincheck()  
			{  
				if (loginform.username.value=="")
				{   alert("用户名不能为空，请重新填写！");
					document.loginform.username.focus();
					return false;
				}
				if (loginform.password.value=="")
				{   alert("密码不能为空，请重新填写！");
					document.loginform.password.focus();
					return false;
				}
				return true;
			}