Stirling Homex Corp. I. Homasote Co., 437 F.2d 87, 88 (2d Cir.1971). It is incumbent on a party to raise the lack of personal jurisdiction. See Zelson Thomforde, 412 F.2d 56 (3d Cir.1969) (district court cannot raise personal jurisdiction seta sponte ). Further, if a party wishes to challenge pe