[jQuery] know if one id are hidden

[jQuery] know if one id are hidden


HI, i work in .net
and in my jquery function want know if mi object are in state hidden
or not...
but this 2 method not work
if($("#check_id").attr("type", hidden)){//......}
or
if ($("#check_id").is(input[type='hidden'])){//......}
what is the right metod??