saving a group of gif files into animated gif using c#

im working on an animation wizard using c#. the idea is to save the group of gif files into one animated gif file. i read that this could be done using the image.saveadd function, the problem is that i couldnt use this function properly.i cant understand what im supposed to do with the encoderparameters parameter. can anybody give me a sample code explaining how to combine two gif files in one animated gif file for instance??