textbox problem

string input = @"
https://mojhosting.net/5937148695/mojfilm.avi
https://mojhosting.net/5937148695/mojfilm2.avi
https://mojhosting.net/5937148695/mojfilm3.avi";

string[] lines = input.Split(
	new[] { System.Environment.NewLine },
	System.StringSplitOptions.None
);

string output = "";

for (int i = 0; i < lines.Length; i++)
{
	int filenameStart = lines[i].LastIndexOf('/') + 1;
	string fileName = lines[i].Substring(
		filenameStart,
		lines[i].Length - filenameStart);
	output += fileName + System.Environment.NewLine + lines[i] + System.Environment.NewLine;
}