My Asus probe only detects my CPU and motherboard temperature, how can I know what is the temperature inside my case?

thanks!

------------------
My stuff:
Asus A7V + Duron 800
128mb PC133
GeForce 2 MX
Turtle Beach Santa Cruz
Quantum 10gb UDMA33 HD
Philips 4x4x32 CDRW
Adaptec AHA-2940AU SCSI
Toshiba 32X SCSI CD-ROM