Difference between glim and glm command in S+

[duangporn.jearkpaporn@asu.edu]

Dear Splus users,

I am a new S-Plus user and I am currently working on generalized linear
model.  I am very confused with functions provided in S-Plus; glim and glm,
particularly when I was trying to adjust for the overdispersion.  Can anyone
please tell me the difference between these two functions?  (Or at least
please suggest any references that might be helpful).  

For you information, I am using S-Plus version 4.5 Window based.  

Thanks in advance,

Duangporn