Image Upload in Byte

Question

I have a datatable containg image that is saved as byte,

I dont want to save image into a folder only saved to datatable.

then I want to check the size of the image not exceed to 500 mb.

WHEN i use this code, i got object reference not set to an instance ..

 

if (fupImage.HasFile != null)

{

string stdid = Session["StdId"].ToString();

int length =fupImage.PostedFile.ContentLength;

if (length > 500 * 1024)

{

Response.Write("Ur image is too large");

}

}

 

I have to upload image when image column of datatable become null value too..

 

 

How can I RESOLVE it ..pls help...Thanks in ADVANCE..:)