[Greasemonkey] GM_xmlHttpRequest question

[Jossie Mann]

I'm creating some new html tags.  I'm trying to have greasemonkey parse 
html pages I create, and whenever it encounters one of these html tags, 
I want to send out a GM_xmlHttpRequest.  Now I've been able to 
accomplish all of that.  However here's where my problem occurs, when 
the data comes back from the server, I want the content that the server 
returns injected into the page where the html tag is located.  My 
problem is, how can I store the association between the html tag and the 
xmlHttpRequest so that when the xmlHttpRequest returns back to the page 
I know which html tag triggered it.

Initially I only had one html tag per page, so I was just able to store 
that one tag in a global variable.  However, after I added multiple tags 
this didn't work as the xmlHttpRequests could return in a different 
order from the page's order.

Second I tried to do a for loop through all the html tags, and set an 
onload event for each html tag.  However, this didn't work.  The first 
html tags onload would occur, but that caused the greasemonkey script to 
stop running and none of the other onloads to even get created.

Is it possible to do what I'm attempting to accomplish through 
javascript and greasemonkey?

Thanks,  Jossie