Iam using 44780 sample code to drive this LCD
1) "sample code" does not necessarily work, much of it has outright errors.
2) if "sample code" 'works' it, usually, only does so under the exact same conditions as the publisher had.
3) The most common resaons that "LCD sample code" does not woprk is oscillator speed and delays in C figured with another compiler - delays in C are, of course, totally wrong in the first place.
4) using "sample code" without an inkling of understanding it is sheer folly.

Erik