the defenses of modification and novation rested, in part, on the existence of an agreement between Schleider and Beal Bank. Beal Bank argues there is no evidence Schleider and Beal Bank agreed on the material terms so as to create a binding contract, such as would support modification or no-vation. We agree. When the parties leave an essential term open for future negotiation, there is no binding contract. T.O. Stanley, 847 S.W.2d at 221. In the present case, there is no evidence Schleider and Beal Bank agreed on the duration of an extension of the loan, a new maturity date, the rate of interest that would apply, or the amount and number of additional payments. Thus, there is no evidence of a binding agreement in the present case. See T.O. Stanley Boot, 847 S.W.2d at 221-22 (<HOLDING>); Gerdes v. Mustang Exploration, 666 S.W.2d
holding that the proper rate for prejudgment interest is the rate fixed by the parties in a contract holding alleged contract to make 500000 line of credit available failed for indefiniteness when no evidence was introduced regarding interest rate of alleged loan or repayment terms holding that where oral loan was silent as to the time of repayment the statute of limitations began to run at the time the contract was made holding that contract failed for indefiniteness because there were essential terms upon which there was no agreement holding unconscionable loan terms with an extraordinarily high interest rate