  The aim of this paper is to present some fixed point theorems for generalized
contractions by altering distance functions in a complete cone metric spaces
endowed with a partial order. We also generalize fixed point theorems of J.
Harjani, K. Sadarangani [J. Harjani, K. Sadarangani, Generalized contractions
in partially ordered metric spaces and applications to ordinary differential
equations, Nonlinear Analysis 72 (2010) 1188-1197] from metric spaces to cone
metric spaces.
