C# GDI+ Code Review/Improvements

We have a relatively simple C# class that generates a chart using [login to view URL] methods based on values in an XML file. The current program is works but we want to improve performance, flexibility and error catching. We are looking for a coder to review the program, implement improvements and document the changes. We will provide the following: 1) An .aspx page which loads and calls the class, and returns the image as a stream. 2) The source code for the image generation class 3) 5 test XML files with the data to be graphed. Specifically: Performance - there is a loop to find the smallest and largest values in order to properly scale y-axis of the chart. Is there an xPath call to avoid the loop? The datatypes and subsequent casts may not be the most most appropriate. Any Advice? Flexibility - currently the chart can accept a wide range of values but expects 10 years worth of numbers. How can we change it so the x-axis is dynamic as well? Error Catching - Currently there are no checks. We need checks for missing or malformed xml and when the calculations are out of range. General Suggestions - Any additional advice is welcome. Please find a sample output jpeg and xml file in the attached zip ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete well documented source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows XP Server, running Microsoft .NET 1.1 and IIS 5. Needs to be compilable using Visual Studio .NET 2003