If I got your question right - you want to update several marked records at the time, right? If so, does this blog article help you in any way (?):
http://axwonders.blogspot.ch/2011/10/loop-through-selected-records-on-ax.html
…because it sound as if you are trying to do exactly this.
P.S. Ravindar*, sorry if I might offend you a bit by saying this, but it feels that you don’t have that much experience in AX development yet, BUT you constantly write some misleading statements here and there… if I am not sure about something, I don’t begin my sentence with “it’s not possible” or something like that. Please, don’t state unverified statements and don’t mislead people in what AX actually can do or can’t do. I would say that if it would have been just this time, but I have noticed already at least 3 episodes where you stated something which is not certainly a truth.*