In United States Fire Insurance Co. V. Hartford Insurance Co., 312 Ill. App. 3d 153, 156, 726 N.E.2d 126, 244 Ill. Dec. 530 (2000), the court refused to rely on the certificate of insurance to decide whether the general contractor was an additional insured under the insurer's additional endorsement blanket provision which, similarly to the one here, required a "written agreement or contract, between the insurer and the additional insured to confer coverage. United States Fire, 312 Ill. App. 3d at 156. The court therefore found no evidence of a written agreement between the parties at or prior to the time of the injury. United States Fire, 312 Ill. App. 3d at 156. However in United States Fire, the written certificate of insurance was issued after the injury took place, and not before, so as to fly in the face of the written agreement requirement as well as its purpose to prevent collusion. United States Fire, 312 Ill. App. 3d at 156. More overridingly, unlike in the present case, in United States Fire, there were no written letters of transmittal or any other documents accompanying and referencing the subcontract or requesting inclusion of the general contractor as an additional insured. United States Fire, 312 Ill. App. 3d at 154. In fact, there was even a contest between the parties as to whether there was an oral agreement to name the general contractor as an additional insured. United States Fire, 312 Ill. App. 3d at 154.