如何使DIV显示在其他Div之上

Question

I upload my code on jsFiddle, you can see it there.

http://jsfiddle.net/SrT2U/2/

When you click on the link, the hidden FAQ section will show up, and it will push other divs down. But that is not what I want, I need all other divs stay where they are, and my hidden FAQ section just float on the top. Not sure how to do it. Not even sure if this should be done in HTML, CSS or jQuery.

My jQuery code:

$(function(){
    $(".OpenTopMessage").click(function () {
        $("#details").slideToggle("slow");
    });
});

HTML code:

<div style="border: 1px solid #000;">
    <span>link</span>
    <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
    <span>link</span>
    <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
    <span>link</span>
    <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
    <span>link</span>
    <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
    <span>link</span>
    <span>&nbsp;&nbsp;|&nbsp;&nbsp;</span>
</div>

<div id="faqBox">
   <table width="100%">
<tr><td><a href="#" id="openFAQ" class="OpenTopMessage">this is hte faq section</a></td>
</tr>
    </table>

    <div id="details" style="display:none">
    <br/><br/><br/><br/><br/><br/><br/><br/>
 the display style property is set to none to ensure that the element no longer affects the layout of the page
 <br/><br/><br/><br/><br/><br/><br/><br/>
    </div>
</div>
<br/><br/>
<div style="background:#c00;">other stuff heren the height reaches 0 after a hiding animation, the display style property is set to </div>  

Answer 1

An easy fix would be to just add position:absolute to your faqBox div.

jsFiddle example

Position:absolute takes the element out of the flow of the document and in this case, allows it to appear on top of your other element and not push it down.

Answer 2

You could use position:absolute on the #details div.

Example: http://jsfiddle.net/SrT2U/9/

You would need to fiddle with the margin to get it to line up.

---

EDIT: Noticing that you are using margin:0 auto; to center the FAQ box. You may need to find another way in order to line up the box.

---

EDIT 2:

I noticed if you placed the FAQ div inside the #faqbox table and then change margin:0 auto; to margin-top: 20px; margin-left:-16px; margin-top: 20px; margin-left:-16px; in the #details div and it all works well.

Example 2: http://jsfiddle.net/SrT2U/13/

NB: placing the div inside the table like so is not code to spec, but it does work re centering the FAQs.

Answer 3

If you want a div to show up on top of other elements without changing others' positions, you need to set it CSS property of position to absolute.

In your css files specify the following:

#details{
    position: absolute;
    left: 100px;//your desired position as regard to the left of your window
    top: 100px;//your desired position as regard to the top of your window
}

You can also do that using jQuery as following:

$(".OpenTopMessage").click(function () {
    $("#details").slideToggle("slow");
    $("#details").css("position", "absolute");
    $("#details").css("left", "40px/*some value*/");
    $("#details").css("top", "40px/*some value*/");
});

If you want to still locate your pop-up box at the center of your window, you can use jQuery to center it as following.

$(".OpenTopMessage").click(function () {
    $("#details").slideToggle("slow");
    $("#details").css("position", "absolute");
    window_width = $(window).width(); //Get the user's window's width
    window_height = $(window).height(); //Get the user's window's height
    $("#details").css("left", (window_width-$("#details").width())/2);
    $("#details").css("top", (window_height-$("#details").height())/2);
});

Then your box will be centered.

Also, you will probably find your button "this is hte faq section" is covered by your div, but you can easily enable closing the pop-up box by adding a close button or add the following code:

$("body:not(#details)").click(function() {
    $("#details").slideToggle("slow");
});

This enables you to click on any part of the page to close the targeted div #details except for the div itself.

Usually, if you are trying to make a pop-up box or dialog, you can try to use other pre-designed plugins, including jQuery UI ( http://jqueryui.com/dialog/ ) or blockUI ( http://www.malsup.com/jquery/block/ ), of which the former only supports dialogs but the latter supports all kinds of pop-up boxes.