f7_keep = false;

function hhh() {
  if (!f7_keep)
    $('#drop1').hide();
}

$(function(){
  $('#drop1').hover(function(){
    f7_keep = true; 
  }, function(){
    f7_keep = false;
    setTimeout(hhh, 500);
  });
});

function f7_showdrop() {
  $('#drop1').show();
}

function f7_hidedrop() {
  f7_keep = false;
  setTimeout(hhh, 500);
}