Javascript error when try to send PM

[Jamsoft]

I am getting a Javascript error when trying to send new private messages on IE. This happened only in one machine; I tried on more than 4 machines which uses same settings and same IE version. Only one machine getting this error. Some of our visitors who using our VB forums getting this error too. I check the security settings on IE, all the machines uses the same settings. I get this error for all the editors.

Error: syntax error
    Source File: http://forums.devshed.com/private.php
    Line: 734, Column: 62
    Source Code:
    	var result = validatePost(formname, formname.title.value, 0, );