// find out if a selected element's is visible.
$visible = $(this,":visible").length; // returns true of false
// find out if a selected element's immediate sibling div is visible.
$visible = $(this).next('div:visible').length; // returns true of false
// hide the selected previous siblings element, <span>hide me</span><element>this</element>
$('+ span', this).hide();
// hide the selected element's child with the class name .class
$(".class",this).hide(); // returns true or false