"Summary judgment is properly granted when the evidence in support of the moving party establishes that there is no material issue of fact to be tried. ( Code Civ. Proc., 437c . . . .) the trial court must decide if a triable issue of fact exists. If none does, and the sole remaining issue is one of law, it is the duty of the trial court to determine the issue of law. ( State Farm Fire & Casualty Co. v. Eddy (1990) 218 Cal. App. 3d 958, 964 267 Cal. Rptr. 379.) Appellate review of summary judgment is limited to the facts contained in the documents presented to the trial court. This court exercises its independent judgment as to the legal effect of the undisputed facts disclosed by the parties' papers. (State Farm Fire & Casualty Co. v. Eddy, supra, 218 Cal. App. 3d at p. 965; Downey Savings & Loan Assn. v. Ohio Casualty Ins. Co. (1987) 189 Cal. App. 3d 1072, 1086-1087 237 Cal. Rptr. 835.)" ( B & E Convalescent Center v. State Compensation Ins. Fund (1992) 8 Cal. App. 4th 78, 88-89 9 Cal. Rptr. 2d 894). In order for a defendant to prevail on summary judgment it has the burden of negating one essential element of the cause of action asserted or to establish an affirmative defense to the claim. In determining whether a defendant has carried its burden, "first, we identify the issues framed by the pleadings since it is these allegations to which the motion must respond by establishing a complete defense or otherwise showing there is no factual basis for relief on any theory reasonably contemplated by the opponent's pleading. Secondly, we determine whether the moving party's showing has established facts which negate the opponent's claim and justify a judgment in movant's favor." ( AARTS Productions, Inc. v. Crocker National Bank (1986) 179 Cal. App. 3d 1061, 1064 225 Cal. Rptr. 203).