Hello Michael,
> As I need to use this project within my office, all users who are using this project can be trusted.
It is the site to be trusted by user systems, not the reverse. Also, you were actually replacing the first back-slash only. Anyway...
Anyway, you know, I have tried it on IE6/Win98 and IE6/WinXP+SP2 and it *works*! Didn't even need to touch my security settings, but if IE7 complains, then you might try to add the site to the trusted list. However, it doesn't work in FX, nor I guess in any non-IE browser.
I have simplified the script a bit, since the replace stuff is unneeded, but have added some error handling. You can see it live here: http://julio.diegidio.name/Sandbox/LocalBrowse.htm
I only have one final doubt, that is that it works for me because it is a plain html page, not an .aspx page. In that case, either you again might try by trusting the site in IE, or you might work-around it with an IFRAME.
Hope this helps, and please let me know if it worked for you! Thanks. -LV