javascript is capable to load data

Question

hai,
this is koteswararao i want to get the data from the backend like a .xl file  and display that data into front end like a gridview the datasource is located in the local system i wish to do this entair process through JavaScript code only if there is possible i know but how to do i don' t know if any one having idea about this send me...
at the same i want little information about layers concept in java script ...
Thanks & Regards,
M.Koteswararao