<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1251">
<title>test</title>
<script type="text/javascript">
<!--
function test(){
alert("работает");
}
function init() {
document.getElementById('but_1').onclick = test;
}
//-->
</script>
</head>
<body onload="init()">
<button class="but_menu" id="but_1">Test</button></a>
</body>
</html>