[R-sig-ME] How to define the fixed and random effects in lmer

[FMH]

Dear All,

I was running lme function on my data as shown below, in which the variables involved are:

########################################
#Pre : Precipitation
#t : time
#group : Group of precipitation
#prec: data set

lme(Pre ~ t| group, data = prec, random = ~ t| group)
#########################################

How could i write the scripts with lmer function with :
1. fixed effects for the intercept and slope and only random effect for the intercept is included
2. fixed effects for the intercept and slope, and random effects for the intercept and slope are included
3. only fixed effect for the intercept and only random effect for the intercept is included
4. only fixed effects for the slope, and random effects for the intercept and slope are included 

Thank you
Fir