Stuck on URI parsing and redirection - HELP

What i need to do is this:

 

 

If a request comes into a VIP and it does NOT have a "?" in the URL, I need to add a "?dom=sp" at the end of the url and then pass it on. Obviously my rule is lame. All it seems to do is add dom=sp and loops it so I end up with a URL thats really long with 9 million dom=sp at the end of it.

 

 

Here is the rule:

 

 

if (http_uri contains "?") {

 

redirect to "http://%h/%udom=sp"

 

}

 

else {

 

redirect to "http://%h/%u?dom=sp"

 

}