Language / -ski/-ska, -scy/ski, -wicz - Polish surnames help [185]

From the entries here, I gather that my fathers name of "Roslanowicz" means son of Roslan. Does anyone know what "Roslan" means or refers to? Is it Ross? Also my grandmothers maiden name was Morawa. I gather from this site that that means daughter of Mor? Is that correct? What name would "Mor" translate to? Last, I haven't read much in surnames ending in "czek." My mom's maiden name is Garczek. What can anyone tell me about its meaning? Thank you