checking if a HTML element is visible or hidden under JQuery

<style type="text/css">
div.nonVisib{
display:none;
}
</style>
<div class="nonVisib"> Your content Here </div>

if( $('div.nonVisib').is(':visible') ) {
    // in case the element is visible 
}
else {
    //  in case the element is hidden 
}

if( $('div.nonVisib').is(':hidden') ) {
    // in case the element is hidden 
}
else {
    //  in case the element is visible
}