Question about BitmaptData to bmp pic conversion post found on this forum

i found this post here which converts bitmapData object to bmp images:

Now that method is done using get method instead of post. so if i try to work it with even a marginally bigger bitmap, the url is too long to work. And from the discussion in there i could gather that i cant send the whole string of bitmap as a string to the server.

Can i not?? if its a string, why cant i simply save it in one variable of a LoadVars object and send it out to the server??