Dynamic Graphs

I am fairly proficient at using Excel but I am attempting a project that is a bit beyond my abilities. I am attempting to create a spreadsheet that will have a dynamic line graph that changes based on a user selected Combo Box. I have a bunch of different products that are all broken down by categories. I want to have 2 combo boxes, the first one will display all of the categories. After the user selects the category the second combo box will be populated with only products from that category. Then, once the user selects the product from that category the chart will show the sales data for that product. I have attached a sample of what they layout of the data is. There will be many more categories and products and several years of sales data in the actual project though.

Thanks for your help.