How to assign seismic load in staad.pro?

dear honorable engineers,

I am learning staad.pro on my self.please someone write to me how can I assign seismic load(both static and dynamic) in staad.pro especially through is1893.Please tell me about seismic defination. When we assign self weight, joint weight,member wt,floor wt in seismic defination, shall we again assign them in Load Case Details?or What is actual meaning?

thanks in advance