Simple Client in C# to test request/response dialogue

C# client application. See screenshot in the attachment. The application is used to test a simple webservice. The client allows to enter and edit a request message (typically XML or plain text) in the Request Textbox. When the 'Send Request' button is pressed, the application sends the request message via a HTTP post message to a webserver URL. The content type must be text/xml. The applicaiton waits for the response (content type text/xml) and displays the response in the Response Textbox. No HTML formatting, just plain text display! All requests that have been sent by the client are stored in files (1 file per request). The requests are accessible for re-transmit. They can be reddisplayed in the Request Textbox by pressing the corresponding Request History Button on the right side of the client window. When the cursor is moved into a request history button, the first 10 lines of the request are shown in a ToolTip rectangle. When the mouse moves out of the button, the ToolTip disappears. The number of request history buttons is unlimited. When the underlying files are deleted on disk (manually with Windows-Explorer), the corresponding Request buttons do not show up any more after a restart of the client.