Superficially, JavaScript looks a bit like Java crossed with Pascal. Strings may be enclosed in either " or '. Semicolons are separators rather than terminators, as in Pascal. there is an explicit function keyword to make the start of each method. Each declaration is explicitly marked with the keyword var, as in languages designed for each of maintenance.

JavaScript causes havoc in pages when you use them off-line if they try to fetch material from the Internet, blocking page rendering. You can disable JavaScript while off-line with the defer parameter. Unfortunately only Opera and Firefox support in properly both on-line and off-line. Mozilla, Netscape ignore it. IE screws it up totally. To be fair, the original definition was that the script generated no output, so it could be postponed, until rendering was finished.

<!-- for conventional HTML -->
<script type="text/javascript" src="myScript.js" defer></script>

<!-- for XHTML -->
<script type="text/javascript" src="myScript.js" defer="defer"></script>