Connection String , AppSetting in WebConfig File and Connection Class in Asp.Net

<connectionStrings>
 <add name="TESTConnectionString" connectionString="Data Source=Test\sql2k5;Initial Catalog=TEST;User  ID=sa;Password=TEST;Connection Timeout=1024;Connection Lifetime=2400;Max Pool Size=10000;Min Pool  Size=0;Pooling=true" providerName="System.Data.SqlClient"/>
</connectionStrings>

<appSettings>
   <add key="SqlServerConnectionString" value="Server=Test\sql2k5;UID=sa;PWD=TEST;Database=TEST" />
   <add key="strServerName" value="Test\sql2k5" />
   <add key="strDatabaseName" value="TEST" />
   <add key="strUserID" value="sa" />
   <add key="strPassword" value="TEST" />
   <add key="CRHtmlViewerPath" value="\TEST\Reports\frmCRHTMLViewer.aspx" />
   <add key="strTempPath" value="\TEST\Temp\" />
   <add key="CrystalImageCleaner-AutoStart" value="true" />
   <add key="CrystalImageCleaner-Sleep" value="60000" />
   <add key="CrystalImageCleaner-Age" value="120000" />
</appSettings>

public class Connection
 {

  public SqlConnection TEST_Conn;
  public SqlTransaction TEST_Trans;

  //string ConnectionString;
  public Connection()
  {
   
  }

  private string Connection_String
  {
   get
   {
    return ConfigurationSettings.AppSettings["SqlServerConnectionString"];   
   }
  }

  public SqlConnection Get_Connection()
  {   
   try
   {
    TEST_Conn  = new SqlConnection(Connection_String);    
    TEST_Conn.Open();
   }   
   catch(Exception ex)
   {
    throw new Exception(ex.Message,ex);
   }
   return TEST_Conn;
  }

  public void Close_Connection()
  {
   try
   {
    if (TEST_Conn!=null)
     TEST_Conn.Close();
   }
   catch(Exception ex)
   {   
    throw ex;
   }
  } 

  public void BeginTransaction()
  {
   try
   {
    TEST_Conn = Get_Connection();
    TEST_Trans  = TEST_Conn.BeginTransaction();
   }
   catch(Exception ex)
   {   
    throw ex;
   }  
  }
  
  public void RollBackTransaction()
  {
   try
   {
    TEST_Trans.Rollback();    
    Close_Connection();
   }
   catch(Exception ex)
   {   
    throw new Exception(ex.Message,ex);
   }  
  }

  public void CommitTransaction()
  {
   try
   {
    TEST_Trans.Commit();
    Close_Connection();
   }
   catch(Exception ex)
   {   
    RollBackTransaction();
    throw new Exception(ex.Message,ex);
   }  
  }
}