<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>

<title></title>

<script language=javascript>
function Checkbox1_OnClick(){
var chk = document.all.item("Checkbox1");
if (chk.checked)
Function1();
else
Function2();
}

function Function1(){
alert("Function1");
}

function Function2(){
alert("Function2");
}
</script>
</head>
<body>
<INPUT id="Checkbox1" type="checkbox" name="Checkbox1" onclick="Checkbox1_OnClick()">
</body>
</html>