Footer position bottom issue

Question 1

here is a fiddle doing what you asked using jQuery: FIDDLE

basically you just compare body and window heights, if body is longer set footer to absolute, if shorter set it to fixed:

$(function () {
    //change this to 'display:none'
    $('.right').css({'display':'static'});
    var footer = $('footer');
    var theDocument = $('body');
    var theWindow = $(window);
    if (theDocument.height() < theWindow.height()) {
        footer.css({
            'position': 'fixed'
        });
    } else {
        theWindow.height();
        footer.css({
            'position': 'absolute'
        });

    }
});

UPDATE:

here is a version that fixes the footer being over the content, you just need to move the footer down by the size of its height

FIDDLE

//######  code inside $(function () {}) will run as soon as DOM loads
$(function () {
    //change this to 'display:static' to add more content
    $('.right').css({'display':'none'});
    //sets a custom event handler to window resize + zoom, which triggers the 
    //footer fix function
    $(window).resize(function(){
        adjust_footer();
    });
    //also call this function as soon as document finishes loading
    adjust_footer();
});
//#####


function adjust_footer(){
    var footer = $('footer');
    var theDocument = $('body');
    var theWindow = $(window);
    //the  +footer.height() checks if there is enough space for footer
    //to stick it as fixed without having it cover content
    if (theDocument.height() +footer.height() < theWindow.height()) {
        footer.css({
            'position': 'fixed',
            //important, or footer will remain misplaced
            'bottom':0
        });
    } else {
        theWindow.height();
        footer.css({
            'position': 'absolute',
            //push footer down and align it to the end of content
            //meaning if footer's height is 50px, it will be pushed 50px
            //from the bottom of the content
            //* remember, bottom attribute aligns the element by its bottom
            'bottom':- footer.height()
        });
    }
}

Question 2

If I understand your question correctly you actually want to position the footer as a fixed element and set bottom to 0px. This will keep it at the bottom of the page no matter what.

position:fixed;
bottom:0px;

Question 3

You can use "fixed" property from CSS and add "bottom:0px;" so its gonna be at the bottom forever ;)

<header>
     <div class="wrap">Header stuff</div>
</header>

<div class="content wrap">
    <div class="left">Left Stuff</div>
    <div class="right">Right stuff</div>
</div>

<footer>
    <div class="inner">Footer stuff</div>
</footer>

And CSS:

header
{
    width:100%;
    height:50px;
    background:green;
}

.content
{
    width:100%;
    background:blue;
}

.content .left
{
    width:30%;
    float:left;
    background:blue;
}

.content .right
{
    width:70%;
    float:right;
    background:yellow;
}

.inner
{
    padding:10px;
}

footer
{
    position:fixed;
    bottom:0px;
    height:40px;
    width:100%;
    background:red;
}

Outcome is here: http://jsfiddle.net/67zR6/1/