Recently, Megahed [1] numerically investigated the influences of variable
viscosity and thermal conductivity on the boundary layer flow and heat transfer
of a non-Newtonian Maxwell fluid over an unsteady stretching sheet with
variable heat flux in the presence of slip velocity. The main aim of the
boundary layer flow and heat transfer study is to calculate the physical
quantities of interest namely, the local skin-friction coefficient and the surface
heat flux. Unfortunately, the definitions of these quantities and the boundary
condition 1 ) 0 ( ' − = θ are wrong .