After I run my code, the Excel process in the Task Manager will not go away. Here is the code:

Sub SavePartNumbersInSession()
Dim ExcelObj As Object
Dim i As Integer
Dim j As Integer

ExcelObj = CreateObject("Excel.Application")

ExcelObj.WorkBooks.Open(sPath + System.IO.Path.GetFileName(MyFile.PostedFile.FileName))

i = 1
j = 2

Session("PartNumbers") = ""

Do Until ExcelObj.Workbooks(1).WorkSheets(1).cells(1, i).value & "" = ""

If ExcelObj.Workbooks(1).WorkSheets(1).cells(1, i).value = "Part Number" Then
ExcelObj.Workbooks(1).WorkSheets(1).UsedRange.Columns(i).NumberFormat = "@"

Do Until ExcelObj.Workbooks(1).WorkSheets(1).cells(j, i).value & "" = ""
If IsNumeric(ExcelObj.Workbooks(1).WorkSheets(1).cells(j, i).value) Then
If Session("PartNumbers") <> "" Then
Session("PartNumbers") &= "|"
End If

Session("PartNumbers") &= CStr(ExcelObj.Workbooks(1).WorkSheets(1).cells(j, i).value)
End If


j = j + 1
Loop
End If

i = i + 1
Loop

ExcelObj.DisplayAlerts = False
ExcelObj.Workbooks(1).Close()
ExcelObj.Quit()

ExcelObj = Nothing
End Sub