FIX PHP Fatal error: Call to a member function find() on a non-object

I have a web form loaded on a GoDaddy server that seems to work fine when loaded on a testing server, but delivers a " Fatal error: Call to a member function find() on a non-object" when loaded to the site on want to use it on. Here is the page: [login to view URL] As an optional part of this project, I need to create a simple calculation from data in two of the fields in this form and place the result third field. By simple, I mean the loan amount divided by the Zestimate to deliver a fraction. For example Loan amount=125,000 Zestimate = $225,000 Result of 125,000/225,000= .56 The LTV field does not exist in the current page/code. It is contained in the attached hmtl code here. It must be intergrated into the PHP for to look something like the attached saple. Please place you bid for fixing the fatal error, or both, but specify what you are bidding on. Thank you!