<img src="http://code.helpor.net/picture/swimming.gif" name="u" border="1" style="filter:alpha(opacity=0)">
<script language="javascript">

var b = 1;
var c = true;

function helpor_net(){
if(document.all);

if(c == true) {
b++;
}
if(b==100) {
b--;
c = false
}

if(b==10) {
b++;
c = true;
}

if(c == false) {
b--;
}
u.filters.alpha.opacity=0 + b;
setTimeout("helpor_net()",50);
}
helpor_net();
</script>


这段代码系图片渐渐显隐,请问如果要在层中的图片有这种效果,要把这段代码放在那里