новый вася,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
</head>
<body>
<script>
function gettop()
{
var a = document.getElementById('div1').style.top;
if (a != '50px') {
document.getElementById('div1').style.top = "50px";
} else {
document.getElementById('div1').style.top = "150px";
}
return false;
}
</script>
<a href="" onclick="return gettop();" style="position: absolute; top: 150px;" id="div1">бла бла бла</a>
</body>
</html>