You need to change to this
if (FileUpload1.HasFile)
{
savepath = Path.Combine(Request.PhysicalApplicationPath, imagefoldr);
savefile = Path.Combine(savepath , FileUpload1.FileName);
FileUpload1.SaveAs(savefile);
}
Note the use of 'savepath' and 'savefile' in this line of code
savefile = Path.Combine(savepath , FileUpload1.FileName);