How to read in a large txt file?

HI,everyone:
I want to read in a large txt file about 180kb. First I use ifstream object ,
just like this ifstream inFile("filename") ;

where filename is the large file's name ,but it seems didn't work .What's wrong with it?
can you help me?
thanks!

[satishvv]

There should be no problem reading in a file of size > 180 KB. I have worked with files of size = 274 KB without facing any problems.
It would be worthwhile to let us see your code which handles the file reading operation together with the error message or the exact description of the problem you are facing. It is difficult to decipher from your message '...but it seems didn't work'.