Rotating Quotes With Text Fading

I've got a simple javascript that rotates quotes randomly. It's very basic, so I wanted to add a fade in/ fade out transition to the text to make it more appealing. I've researched around the net and have had trouble finding sources to help me out. Here is the code.

<script language="JavaScript">
function rotateEvery(sec)
{
var Quotation=new Array()

// QUOTATIONS
Quotation[0] = '...The big brown fox jumped over the tall fence'
Quotation[1] = '...The wind is blowing cold snow across the dark black road'
Quotation[2] = '...Fall has many colors and black is not one of them'
Quotation[3] = '...the blue bird lives in the big red barn'
Quotation[4] = '....Mr. Grant really believes that the Bull’s skills, which are widespread, are utterly godlike even though he acts like he doesn’t think so'
Quotation[5] = 'Sixth quotation'
Quotation[6] = 'You can add <b>as many</b> quotations <b>as you like</b>'

var which = Math.round(Math.random()*(Quotation.length - 1));
document.getElementById('textrotator').innerHTML = Quotation[which];

setTimeout('rotateEvery('+sec+')', sec*5500);
}
</script>