//-------常用的JS

function check() {
	if (login.username.value=="")
		{   alert("Pls fill in username first");
			login.username.focus();	    
			return false;
		}
	if (login.password.value=="")
		{   alert("Pls fill in the password first");
			login.password.focus();	    
			return false;
		}
}