Any way to Trade using OBV SAR and William %R?

Dear friends,
I was reading a post where analysis of GAIL was given using SAR OBV and William %R.

Is there any concrete way/methodology to trade using the above three indicators, or including more indicators with them.

Any afl to find SL or Risk/Reward ratio?

included chart of Era cons with sar obv and william %R. (Thanks karthik for guiding me how to write afl (till now reached only basics.....) slow student, eh...)

regards
ashutosh

in metastock 8, sar for stoploss, obv holding ..not going down and william%r[10]..on eod moving up from 20 to 30...as buy signal i trade in 2005 jan-march
with good return in group a share.