Asterisk win 32?

hi guys
i have a question about the ASTDB
i want to check for an existing key in the ASTDB and i found out that there is a function called DB_EXISTS() but it seems not to be working with me and I also know that the SET() funcion goes to priority 101+n if it tries to get a non existing key but it is not working either

here is a sample code and hope some body helps
exten => 700,1,answer()
exten => 700,2,Set(COUNT=1)
exten => 700,3,Set(EXIST = ${DB_EXISTS(customers/${COUNT} )})
exten => 700,4,SayNumber(${EXIST})

this is the error which i recieve "saynumber requires an argument "

shouldn’t ${EXIST} have one of two values 0 or 1

thanks

VIP P.S
i am using asterisk win32 version 1.2 with xlite soft phone