<script type="text/javascript">
$(document).ready(function() {
$("#a1").appendTo($("#a2"));
});
</script>

<div id="a1">
<script type="text/javascript">
alert('a1');
</script>
</div>

<div id="a2">
</div>

<div id="a1">
<script type="text/javascript">
loaded = false;
if (loaded == false) {
alert('a1');
loaded = true;
}
</script>
</div>

var loaded = false;
$(document).ready(function() {
if (!loaded) {
alert('a1');
loaded = true;
}
});