How to get database backup on running website on click of a button using asp.net

How to get database backup on running website on click of a button using
asp.net

Code which I m using for button
protected void btn_backup_Click(object sender, EventArgs e) { try {
Class_Backup objbackup = new Class_Backup(); objbackup.BackUpPath =
"SalvageManager" + DateTime.Now.ToString().Replace("/", "").Replace(":",
"").Replace("-","").Replace(" ",""); objbackup.BackupData(); if
(objbackup.OperationStatus != false) {
Response.ContentType = "application/bak";
Response.AppendHeader("Content-Disposition", "attachment;
filename=" + objbackup.BackUpPath);
Response.TransmitFile(Server.MapPath("~/DataBaseBackUp/" +
objbackup.BackUpPath));
Response.End();
//Response.Redirect(Server.MapPath("~/DataBaseBackUp/" +
objbackup.BackUpPath),false);
}
else
{
lbl_message.Text = objbackup.ErrorMessage;
}
}
catch(Exception ex)
{
lbl_message.Text = ex.Message;
}
}
When I click on button following error occured
Error : Cannot open backup device
'D:\INETPUB\VHOSTS\salvagemanagers.com\httpdocs\DataBaseBackUp\SalvageManager8_19_2013_12_18_01_PM'.
Operating system error 3(The system cannot find the path specified.).
BACKUP DATABASE is terminating abnormally.