Capacitor Markings

Hi,
I was just wondering weather it was possible to interchange a small disk ceramic capacitor, (.001µF and .01µF) for an MKT polyester of the same value?
Can someone tell me the value of an MKT marked '100nJ100' or perhaps a formula fo decoding them?
Thanks, Mick.

100nJ100 is 100nF (0.1uF), J is 5% tolerance (K is 10% and M is 20%) and the 100 as the suffix is 100V max voltage rating.

Check this out for a longer discourse on capacitor markings:

Twisted Pair Forum / Capacitor Nomenclature

Dean