You will have to create an HTML page and put your JavaScript code within that page, so it executes when the page loads.
First way
<html>
<head>
<script language="JavaScript">
<!--
alert ("4")
//-->
</script>
</body>
</html>
Second way
<html>
<head>
<script language="JavaScript">
<!--
var a = "2";
var b = "2";
alert( Number(a) + Number(b) );
//-->
</script>
</body>
</html>
Third way
<html>
<head>
<script language="JavaScript">
<!--
alert( Number(2) + Number(2) );
//-->
</script>
</body>
</html>
last way but the most simple
<html>
<head>
<script language="Javascript">
<!--
alert( 2 + 2 );
//-->
</script>
</body<
</html>
I used this page to encapsulate the code.
Blogger is not to happy about having raw code so using this tool will save you a bunch of & l t ; & l t ; etc
If you need to know more about reserved characters read up
I used this for HTML tags.
I used this for the Math object Information.
Right from the horses mouth Core JavaScript Guide
