Mold Cavity Question

Hello SolidWorks Forum,

     I am very new to SolidWorks and I have a question. I have searched through the forum and I couldn't find any answers so if this is a repost I apologize.  I have made a mold of a part using parting lines and parting surfaces and the like. I am only interested in the cavity portion of the mold, truth be told I really only want the negative of the part I made. Is it possible for me to save the cavity portion of the mold as its own part, and if so how do I do it? I am using SolidWorks 2009 if that matters.

Thank you in advance,

Aaron Cotton

SolidworksPlastics And Mold Design