Make sure your CSS rule for #options-dropdown is display:none; at first - this will make sure that its hidden when the page loads.
Copy and paste the following functions to your JS file
Code:
function toggleDrop() {
$(#options-dropdown).toggle();
}
function hideDrop() {
$("#options-dropdown").hide();
}
Add the following to the div#options - onclick="toggleDrop();" - this will allow for it to show when the user clicks on the div#options
And add this to the other elements of the website that aren't part of the div#options onclick="hideDrop();"
Even though it might not be the most practical way to have to add the hideDrop(); to the other elements, it does what you wanted.
I hope this helps you out