javascript error of unterminated string

I see two potential problems here.

1. JavaScript, like many other programming languages, uses the " character to mark the beginning and the end of a string. Your hintbox text contains a ", so when JavaScript encounters it, it thinks that your string has ended. To fix the problem, you should refer to each " in your string as \". This tells JavaScript that you don't intend to end the string, but rather you plan to put a " inside your string.

2. Similarly, JavaScript does not allow you to place a "paragraph break" directly inside a string. Instead, you must type \n each time you want a carriage return inside your string.

So, here is how you should define your hintbox string:

hintbox = "Hemmed Finish: Every side/edge (1/2\" to 2\") of the banner are folded and glued (special vinyl solution) or heat pressed. This is the most common and best finish option.\n\nStitched Finish: Every side/edge (1\" to 2\") of the banner are folded in the back and stitched/sewed with white thread. This is not a common option as thread can be seen on the banner.";

This is typically called "escaping strings", and a quick Google should give you much more information on the toppic.

Happy programming!

Check this :

onMouseover="showhint('Hemmed Finish: Every side/edge (1/2\'\' to 2\'\') of the banner are folded and glued (special vinyl solution) or heat pressed. This is the most common and best finish option.Stitched Finish: Every side/edge (1\'\' to 2\'\') of the banner are folded in the back and stitched/sewed with white thread. This is not a common option as thread can be seen on the banner', this, event, '250px')"

you do not need to escape : brackets like (

<script type="text/javascript">
<!--//
function alert2()
{
alert ("Don't forget the curly "+
"brackets - \nThey are essential!");
}
//-->
</script>

Whilst the example works for me, it's pretty ugly. Avoid inline event handlers and the crazy escaping problems that come with them. Put the data elsewhere, such as in a JS variable or an attribute value where appropriate. For the case of a tooltip, the title attribute is best:

<span title="Hemmed Finish: Every side/edge (½″ to 2″) of the banner are folded and glued (special vinyl solution) or heat pressed. This is the most common and best finish option.&#10;&#10;Stitched Finish: Every side/edge (1″ to 2″) of the banner are folded in the back and stitched/sewed with white thread. This is not a common option as thread can be seen on the banner.">
    finish options...
</span>

Whilst that works as a tooltip in itself, you can use progressive enhancement to replace that native-HTML tooltip with a scripted one if you want eg. the more flexible styling that comes with it:

var spans= document.getElementsByTagName('span');
for (var i= spans.length; i-->0;)
    if (spans[i].title)
        replaceTitle(spans[i]);

function replaceTitle(element) {
    var title= element.title;
    element.title= '';
    element.onmouseover= function(event) {
        showhint(title, this, event||window.event, '250px');
    };
    element.onmouseout= function(event) {
        hidehint(...);
    };
}

You have to escape " characters. So instead of " use \" (backslash). You could use the new line character to create the paragraph \n or if your tooltip is capable of displaying html use

or
for the paragrahps.

I suggest you also check out jquery tooltip Tooltip.