Hi Abdul Aziz,
If you need urgent help, you should call us and pay for our time.
If not, please be patient. We respond to 90% of all posts. Sometimes it takes a few days or a week though.
Certainly saying your request is urgent will make us ignore you. Since you are not following the protocol - pay people if you need urgency. For free stuff, please don't expect people to bend over backwards to spend their valuable time to help you in an urgent fashion. That's just rude.
Now, to answer your question...
First of all. Full trust forms are not a best practice. Less than 5% of all forms out there should be full trust. If you are using ShP 2010 you can use the file attachment control (out of box) to attach documents. That can be published to browser just fine as Domain Trust. No code needed. Please do that and stop writing code.
We have lots of demos showing this, for example the YouTube video I did in February of 2012 shows attaching an image and converting it to a link. That demo uses our qRules plugin (which is code, but publishes domain trust just fine). You don't need that for what you are doing though. Just use stock file attachment.
If you are doing ShP 2007, the control doesn't exist. In that case, I suggest you use a hyperlink control and default it to the document library where you want people to select the form. You can then use a dropdown to list the files in the doc lib and have them select one of those. Then, you have a rule that appends the selection to your hyperlink and voila you have a form that references a file in a doc lib. No attachment, no code, all just stock InfoPath out-of-box domain trust.
Life is easy. Just smile and have a good one.