<html>
<head>
<script language="JavaScript" type="text/javascript">
function toggleButton(thisButton)
{
thisButton = document.getElementById(thisButton);
if (thisButton.disabled == false) {thisButton.disabled = true;}
else {thisButton.disabled = false;}
}
</script>
</head>
<body>
<form>
<input type="checkbox" onclick="toggleButton('btnTest');">
<input type="button" name="btnTest" disabled="disabled" value="Test Button">
</form>
</body>
</html>