css3 transiton

div
{
width:100px;
height:100px;
background:yellow;

transition-property:width;

transition-duration:1s;

transition-timing-function:linear;  // transition-timing-function: linear|ease|ease-in|ease-out|ease-in-out|cubic-bezier(n,n,n,n);

transition-delay:2s;

/* Firefox 4 */

-moz-transition-property:width;
-moz-transition-duration:1s;
-moz-transition-timing-function:linear;
-moz-transition-delay:2s;
/* Safari and Chrome */
-webkit-transition-property:width;
-webkit-transition-duration:1s;
-webkit-transition-timing-function:linear;
-webkit-transition-delay:2s;
/* Opera */
-o-transition-property:width;
-o-transition-duration:1s;
-o-transition-timing-function:linear;
-o-transition-delay:2s;
}

div:hover
{
width:300px;
}