??

英[?b?kgra?nd] 美[?b?k?ɡra?nd]

n.(?? ?) ???; ?? ??; ?z?n ] 美[ p??z???n]

n. ??, ??, ??

vt. ??... ??? ???...; ??: position ????: positioning ????: position ????: position

javascript backgroundPosition? ???

??: ?? ???? ??? ???????.

??: ??Object.style.BackgroundPosition=position

????: x% y%, ? ?? ?? ?? ??, ? ?? ?? ?? ?????. ?? ??? 0% 0%???. ??? ??? 100% 100%???. ??? ?? ???? ?? ?? 50%? ???. ?? ?? ???? ??? ? ????.

javascript backgroundPosition? ?

<html>
<head>
<style type="text/css">
body
{
background-color:#FFCC80;
background-image:url(http://img.php.cn/upload/article/000/005/656/5af270fd37755429.jpg);
background-repeat:no-repeat
}
</style>
<script type="text/javascript">
function changePosition()
{
document.body.style.backgroundPosition="bottom center";
}
</script>
</head>
<body>

<input type="button" onclick="changePosition()"
value="Change background-image position" />

</body>
</html>

???? ?? ?

??? ????? ??? "???? ??" ??? ?????