I'm unable to view the full window while running test scripts in casperjs using slimerjs engine . could any one please help me to increase the mozila browser window size
Sure, use the phantom/slimer viewportSize option in casper :
casper.options.viewportSize = {width: 1600, height: 950};
Or the casper function :
casper.start(url)
.viewport(1600,1000)
.{...}
With the function you can easily change the window size during steps of a scenario.
And the scrollTo(), srollToBottom() functions should help you too : http://casperjs.readthedocs.org/en/latest/modules/casper.html#scrollto