SUp 2.1 HWC - Custom.js - read user credentials

Hi folks,

a small question, maybe there is also such a small answer available...

I wondering how to get the SUPUsername written to a key?

I was trying something like this in Custom.js, method customAfterWorkflowLoad()

(uname is the key/field to show)

var user = document.getElementById("uname");
var supUserName = getURLParam("supusername");
        if(supUserName){
            user.value = supUserName;
        } 

getURLParam("supusername") does not work...

Any Idea?

Regards,

Aksel