asterisk users - Feb 2005 - Help with dial command and h, H and g parameters

I'm trying to find some "live" examples on how to use the h, H and
g
parameters on the dial command 
(http://www.voip-info.org/wiki-Asterisk+cmd+dial)

Any ideas? I was testing with the code below but after pressing * 
nothing happens (only after a long pause the "goodye" file was played)

[testset]
exten => 1023,1,NoCDR()
exten => 1023,2,Dial(SIP/1023,30,Hg)

exten => h,1,Background(goodbye)
exten => h,2,Hangup

exten => i,1,Hangup
exten => t,1,Hangup