Saveas Dialog box

Hello All

I have a js function which load a whole letter in a div and have a print button that allow the user to print the letter. I have to add an option that allow the user to save the letter in a location.I was trying to do something like a saveas dialog which the user can save the letter at any location.Can anyone please help me to achieve it.Note that I am using IE8. Thank you, below is part of my code.

<script type="text/javascript">
window.onload =function()
{
var content = window.opener.LoadLetterinPreview();
document.getElementById("print").innerHTML=content;
}
</script>

<div id="print" style="border:1px red solid; width:650px;"></div>

The web browser already has a "Save as" menu that is more reliable and secure than allowing Javascript to trigger a file save.