The reason you experience this problem is that on first submit you set RadUpload1.TargetPhysicalFolder = folderpath. So, on next submit the selected file is first automatically saved because you have specified a TargetPhysicalFolder and then it gets saved by your code f.SaveAs(targetFileName). Why do you set RadUpload1.TargetPhysicalFolder? Specifying TargetPhysicalFolder/TargetFolder property activates the process of automatically saving the uploaded file to the specified folder.
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