most of clint what they they do  is  they try to sum of call and put ltp of fixed  strike price which will plot in amibroker, by this method you will not able to judge that  currrent atm straddle  premimum value is high or low with respect to over  time period,
option selling strategies is deployed  when current combined premimum vlaue is  high  with respect to over the period of time,
this will give higher sucess and perfect entry .how to do that?
1>in robo add two scirpt  ATMBNCE  AND ATMBNPE  and ATMNFCE and ATMNFPE which will give ltp of current ATM call and put,
BN Is for banknifty and NF is used for NIFTY
 2>Now to get combined value of atmbnce and atmbnpe we add new formual scirpt @ATMBNDXIII
 While creating formula dont forget to selct create amibroker ltp file 
3> now go to  rtqoute pro and clik on excel2ami then one new window exe will open which will push @atmbndxIII data in amibroker realtime
 
                                                 
4> NOW @atmbndxIII graph is being ploted in amibroker, this graph will give u clear cut picture when combined premum is high  or what value of combined premum will face resistanse level   etc, make enter into trade at those level  and do trade adjustmnet further

How to do auototrade short  straddle ?