  The present day observations favour a universe which is flat, accelerated and
composed of $\sim 1/3$ matter (baryonic + dark) and $\sim 2/3$ of a negative
pressure component, usually referred to as dark energy or quintessence. The
Cosmic Lens All Sky Survey (CLASS), the largest radio-selected galactic mass
scale gravitational lens search project to date, has resulted in the largest
sample suitable for statistical analyses. In the work presented here, we
exploit observed image separations of the multiply imaged lensed radio sources
in the sample. We use two different tests: (1) image separation distribution
function $n(\Delta\theta)$ of the lensed radio sources and (2)
${\dtheta}_{\mathrm{pred}}$ vs ${\dtheta}_{\mathrm{obs}}$ as observational
tools to constrain the cosmological parameters $w$ and $\Om$. The results are
in concordance with the bounds imposed by other cosmological tests.
