[Freeswitch-users] Passing Variables in FS

Hi, I'm newbie in FS. As far as I know for setting up custom variables in FS we use this syntex in dialplan XML i.e. <action application="set" data="ABC='value'"/> But when I call this variable using eval application i.e. <action application="eval" data="${ABC}"/> the value I get from variable ABC is undefined means no values are passed to the variable. So kindly do let me know how I can pass values in variables in FS. -- Regards, Ahmed Munir