Hi
You may used a web control named file control in asp.net 2.0 that is better than the html control file in the asp.net 1.0 , so u can use its data by the property File1.PostedFile
which File1 is the control .
if you want to get the lenght of the posted file u can use
File1.PostedFile.ContentLength
To return the bytes exist in the file use the following code :
int len=File1.PostedFile.ContentLength;
byte[] bData=new byte[len];
File1.PostedFile.InputStream.Read(bData,0,len);
Now the array bData is full of bytes in the file , so u can stream it and put check u want.
Note: If u didn't use the web control and used the html control
right click on it and check run as server control and complete the previous steps.