Hello:

 

And

 
Does the page http://mydomain.com/yourpage.aspx contains the <iframe src=http://chat.mydomain.com/../Ch_MainForm.Aspx?ChannelId=xxx></iframe> ?

where does the script ' document.domain="mydomain.com" ' run ? the  yourpage.aspx  or  CH_MainForm.Aspx ?

 

Regards , Terry .