My application makes use of frames and iframes.

In two frames, Frame1 and Frame2, I have a particular value to be captured into a parameter (using web_reg_save_param).
Value from Frame1 is the default that is returned. But I need the value in Frame2.
I am just not able to retrieve the value using RelFrameID. (I keep getting a warning "No buffer having RelFrameID=<value> has been received").

What are the possible reasons this is happening? Also, where can I get more information about 'RelFrameID' (Other than the function reference and regular documentation)