Q: Hover or click on one div to affect another I'd like to have ability to hover on one div to affect another.
<div id="a">1</div>
<div id="b" style="display:none;">2</div>

How to hover #a and make #b appear?
I'd like a css3 solution but jquery also is good.

A: This works in chrome:
http://jsfiddle.net/iambriansreed/uQfKw/
HTML:
<div id="a">1</div>
<div id="b">2</div>

CSS:
#a + #b {
    display: none;

}
#a:hover + #b {
    display: block;

}


A: $("#a").on({
     mouseenter: function() {
         $("#b").show();
     },
     mouseleave: function() {
         $("#b").hide();
     },
     click: function() {
         alert('Holy crap! Someone clicked me!');
     }
});

If you place #b inside #a, you could do it with CSS, otherwise the jQuery solution above should work (with jQuery 1.7+).

A: A css solution would need them to be like this:
<div id="a">1
    <div id="b">2</div>
</div>

the css to show the block would be:
#a:hover #b{
    display: block;
}

You can see both of the examples here: http://jsfiddle.net/skip405/L93x7/
