What does this error message mean?

[hungrymouth]

Hey guys I'm getting this error message in my code. It says: 1>c:\users\caconnects\documents\visual studio 2012\projects\fproj\fproj\header.h(278): warning C4244: '=' : conversion from 'std::streamoff' to 'int', possible loss of data

And this is the part that says where the error is coming from:

 LengthOfFile = ReadWrite.tellg();

I'm not sure what I have to do to fix this any idea? My code is running but the thing if I try to edit something, then save it and compile it, it won't compile what I edited.

[ZuK]

It's warning you that the return value from tellg() might not fit into an int.
Kurt