how to do comment on js file code example

Example 1: comment out in javascript

<script type="text/javascript">
<!--
document.write("I have multi-line comments!");
/*document.write("You can't see this!");
document.write("You can't see this!");
document.write("You can't see this!");
document.write("You can't see this!");
document.write("You can't see this!");
document.write("You can't see this!");
document.write("You can't see this!");*/
//-->
</script>

Example 2: js comment

//This does not effect the code.
var something = "But this does effect the code!";