Code for uploading any file in the file system and method calls depending on the type of file such as Excel? Please advise your example:

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.IO;

namespace FileUploader
{
	/// <summary>
	
	/// This product is free for all. don't economic use.
	/// </summary>
	public class frmDefault : System.Web.UI.Page
	{
		public string filesurl="files/";
		//public string filesurl="http://www.files.somee.com/files/";
		protected System.Web.UI.WebControls.Label lblFileUrlHint;
		protected System.Web.UI.WebControls.Button btnUpload;
		protected System.Web.UI.HtmlControls.HtmlInputFile htmInput;
		protected System.Web.UI.WebControls.Label lblErrorUploading;
		protected System.Web.UI.WebControls.Label lblErrorFileExists;
		protected System.Web.UI.WebControls.Label lblErrorFileExt;
		protected System.Web.UI.WebControls.HyperLink lnkFileUrl;
		protected System.Web.UI.WebControls.HyperLink lnkUploaded;
		protected System.Web.UI.WebControls.Label lblLargeFile;
		protected System.Web.UI.WebControls.Label lblUploaded;
	
		private void Page_Load(object sender, System.EventArgs e)
		{
			//filesurl=Request.Url.LocalPath+"/files/";
			htmInput.Accept="image/*";
			//this sh*ts, need to be shut up.
			lblErrorUploading.Visible=false;
			lblErrorFileExists.Visible=false;
			lnkFileUrl.Visible=false;
			lblFileUrlHint.Visible=false;
			lblErrorFileExt.Visible=false;
			lblUploaded.Visible=false;
			lblLargeFile.Visible=false;
			// Put user code to initialize the page here
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.btnUpload.Click += new System.EventHandler(this.btnUpload_Click);
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion
		
		private void SaveFile(string strPath, ref byte[] Buffer) 
		{ 
			//save file to server
			FileStream myFile = new FileStream(strPath, FileMode.Create); 

			myFile.Write(Buffer, 0, Buffer.Length); 

			myFile.Close(); 
		}
		private bool LocalFilePath(string file,out string fpath,out string url)
		{
			//generate local file path
			string fname=System.IO.Path.GetFileName(file);
			string local=Server.MapPath("files\\");
			string ext=System.IO.Path.GetExtension(file);
			string result=local+fname;
			if (System.IO.File.Exists(result))
			{
				fname=System.IO.Path.GetFileNameWithoutExtension(file);
				for (int i=0;i<50;i++)
				{
					result=local+fname+i.ToString()+ext;
					if (!System.IO.File.Exists(result))
					{fname=fname+i.ToString()+ext;
						break;
					}
				}
				url=filesurl+fname;
				fpath=result;
				if (System.IO.File.Exists(result))
					return false;
				else
					return true;
			}
			else
			{
				url=filesurl+fname;
				fpath=result;
				return true;
			}
		}

		private void btnUpload_Click(object sender, System.EventArgs e)
		{
            const string accept = "*.png;*.jpg;*.gif;*.zip;*.rar;*.Docx;*.xlsx";
			if ( htmInput.PostedFile != null ) 
			{ 
				string local,url,ext;
				HttpPostedFile myFile = htmInput.PostedFile;
				//test file laws
				ext=Path.GetExtension(myFile.FileName);
				if (myFile.ContentLength>(4*(1024*1024)))
				{
					lblLargeFile.Visible=true;
					return;
				}
				if (accept.IndexOf(ext.ToLower())==-1)
				{
					lblErrorFileExt.Visible=true;
					return;
				}
				if (myFile.ContentLength==0)
				{
					lblErrorUploading.Visible=true;
					return;
				}
				//recive files length
				int nFileLen = myFile.ContentLength;
				byte[] myData = new byte[nFileLen]; 
				myFile.InputStream.Read(myData, 0, nFileLen);
				//test file size law
				if (!LocalFilePath(myFile.FileName,out local,out url))
				{
					lblErrorFileExists.Visible=true;
					return;
				}
				//and save it
				SaveFile(local,ref myData);
				//now go and F**k it
				lnkFileUrl.Text=System.IO.Path.GetFileName(url);
				lnkFileUrl.NavigateUrl=url;
				lnkFileUrl.Visible=true;
				lblFileUrlHint.Visible=true;
				lblUploaded.Visible=true;
			} 
			else 
			{ 
				//Oh! No! sending error!
				lblErrorUploading.Visible=true;// Fail 
			} 

		}

	}
}