URL field in HSG

[xen]

This is an excellent tool and is a great help when helping friend over the network to understand what I mean (a picture says more than a tousand words - right?). And it works just fine as long as I leave the URL field empty. As soon as I enter an URL string of any kind it outputs a message saying that  it's a bad url
My questions are:

-Is this field an input field or is it som kind of output (copy and paste)?
-How can I use this field?

/xen

[rejetto]

if you enter "foo" in the url field
then your friend will have to append "foo" to the URL to see the picture

this is equivalent to a password, only who knows "foo" can see the picture