holding that although the court declined to consider a stock purchase agreement, offering memorandum and warrant on a Rule 12(b) motion to dismiss, it could have viewed them without converting that motion into one for summary judgment where the non-moving party had notice of these documents because they were either in their possession or they had used them in bringing the action

finding that leave may be denied where amendment would be futile

noting that the court may also consider documents upon which the complaint relies and which are integral to the complaint

noting that a court ruling on a Rule 12(b) motion may consider documents which are referred to in the Complaint and upon which [the plaintiff] relies in bringing the action, without converting it to a motion for summary judgment

Noting that "[w]here plaintiff has actual notice of all the information in the movant's papers and has relied upon these documents in framing the complaint the necessity of translating a Rule 12(b) motion into one under Rule 56 is largely dissipated."