<html>
<head>
<title></title>
<script type="text/javascript">
function countdivs(divname) {
var i = 0;
while (document.getElementById(divname+i)) {
i++;
}
alert(i);
}
</script>
</head>
<body>
<div id="ne6to0">ne6to0</div>
<div id="ne6to1">ne6to1</div>
<div id="ne6to2">ne6to2</div>
<div id="ne6to3">ne6to3</div>
<input type="button" onclick="javascript:countdivs('ne6to')" value="преброй">
</body>
</html>