C# Visual Studio

Retail Price Calculator

Create an application that lets the user enter an item's wholesale cost and its markup percentage. It should then display the items retail price. For example:

If an item's wholesale cost is $$5\mathrm{.}00$ and its markup percentage is $100$ percent, then the item's retail price is $$10.$

If an item's wholesale cost is $$5\mathrm{.}00$ and its markup percentage is $50$ percent, then the item's retail price is $$7\mathrm{.}50.$

The program should have a method named CalculateRetail that receives the wholesale cost and the markup percentage as arguments and returns the retail price of the item.

my project keeps showing error values