AGI running under Meetme Background

Hi All,
I had a requirement to run an agi script as background during a conferencing call with meetme . Read a couple of doc about MEETME_AGI_BACKGROUND variable and tried out it but doesnt seems to be working.The situation i want to call a URL periodically while the conferencing taking place via AGI. If any one have experience on this please help me to solve this.
my code is like below.

[test] exten => s,1,Set(MEETME_AGI_BACKGROUND= test_background.php) exten => s,n,MeetMe(1234,bqF) exten => s,n,Hangup

When i execute the code the conference is not happening. After executing the AGI script its getting disconnected .

Howdy,

What part isn’t working?

The script isn’t being called, or it’s not functioning?

Tried removing the space after your equals sign?

Sure you’ve only got DAHDI-based channels in that conference?