File Upload Problem

Hi everyone. I am new to both this forum and to the world of web programming. I have a clsUPLOAD code that uploads and renames files for me. Is it possible for me to add the maximum file size limit (I want to limit the file upload to 512KB) and limit the dimensions of the image to 150 X 150 pixels? If yes, what ASP/VBScript function could do so? Following is my code.
I have tried to fix this on my own but couldn't get it. I need some help.

Thanks in advance

clsUPLOAD.asp (This is the include file)

Code:

<%
' ------------------------------------------------------------------------------
' Container of Field Properties
Class clsField
	Public FileName
	Public ContentType
	Public Value
	Public FieldName
	Public Length
	Public BinaryData
End Class
' ------------------------------------------------------------------------------
Class clsUpload
' ------------------------------------------------------------------------------
	Private nFieldCount
	Private oFields()
	Private psFileFullPath
	Private psError
	Private psFileInputName
' ------------------------------------------------------------------------------
	Public Property Get Count()
		Count = nFieldCount
	End Property
' ------------------------------------------------------------------------------
	Public Default Property Get Field(ByRef asFieldName)
		Dim lnLength
		Dim lnIndex
		
		lnLength = UBound(oFields)
		
		If IsNumeric(asFieldName) Then
			If lnLength >= asFieldName And asFieldName > -1 Then
				Set Field = oFields(asFieldName)
			Else
				Set Field = New clsField
			End If
		Else
			For lnIndex = 0 To lnLength
				If LCase(oFields(lnIndex).FieldName) = LCase(asFieldName) Then
					Set Field = oFields(lnIndex)
					Exit Property
				End If
			Next
			Set Field = New clsField
		End If
	End Property
' ------------------------------------------------------------------------------
	Public Function Exists(ByRef avKeyIndex)
		Exists = Not IndexOf(avKeyIndex) = -1
	End Function
' ------------------------------------------------------------------------------
	Public Property Get ValueOf(ByRef avKeyIndex)
		Dim lnIndex
		lnIndex = IndexOf(avKeyIndex)
		if lnIndex = -1 Then Exit Property
		ValueOf = oFields(lnIndex).Value
	End Property
' ------------------------------------------------------------------------------
	Public Property Get FileNameOf(ByRef avKeyIndex)
		Dim lnIndex
		lnIndex = IndexOf(avKeyIndex)
		if lnIndex = -1 Then Exit Property
		FileNameOf = oFields(lnIndex).FileName
	End Property
' ------------------------------------------------------------------------------
	Public Property Get LengthOf(ByRef avKeyIndex)
		Dim lnIndex
		lnIndex = IndexOf(avKeyIndex)
		if lnIndex = -1 Then Exit Property
		LengthOf = oFields(lnIndex).Length
	End Property
' ------------------------------------------------------------------------------
	Public Property Get BinaryDataOf(ByRef avKeyIndex)
		Dim lnIndex
		lnIndex = IndexOf(avKeyIndex)
		if lnIndex = -1 Then Exit Property
		BinaryDataOf = oFields(lnIndex).BinaryData
	End Property
' ------------------------------------------------------------------------------
	Private Function IndexOf(ByVal avKeyIndex)
		Dim lnIndex
		
		If avKeyIndex = "" Then
			IndexOf = -1
		ElseIf IsNumeric(avKeyIndex) Then
			avKeyIndex = CLng(avKeyIndex)
			If nFieldCount > avKeyIndex And avKeyIndex > -1 Then
				IndexOf = avKeyIndex
			Else
				IndexOf = -1
			End If
		Else
			For lnIndex = 0 To nFieldCount - 1
				If LCase(oFields(lnIndex).FieldName) = LCase(avKeyIndex) Then
					IndexOf = lnIndex
					Exit Function
				End If
			Next
			IndexOf = -1
		End If
	End Function
' ------------------------------------------------------------------------------
Public Property Let FileFullPath(sValue)
	psFileFullPath = sValue
End Property
'___________________________________________________________________________________
Public Property Get FileFullPath()
	FileFullPath = psFileFullPath 
End Property
' ------------------------------------------------------------------------------
Public Property Let FileInputName(sValue)
	psFileInputName = sValue
End Property
' --------------------	----------------------------------------------------------
Public Function Save()
	if psFileFullPath <> "" and psFileInputName <> "" then
		'Save to connectionless client side recordset, write to stream,
		'and persist stream.

		'would think you should be able to write directly to
		'stream without recordset, but I could not get that to work

		On error resume next
		binData = o.BinaryDataOf(psFileInputName)
	
		set rs = server.createobject("ADODB.RECORDSET")
		rs.fields.append "FileName", 205, LenB(binData)
		rs.open
		rs.addnew
 		rs.fields(0).AppendChunk binData 
		
		if err.number = 0 then
			set objStream = Server.CreateObject("ADODB.Stream")
  			objStream.Type  = 1
   			objStream.Open
 			objStream.Write rs.fields("FileName").value 
			objStream.SaveToFile psFileFullPath, 2
			objStream.close
			set objStream = Nothing

		ENd if
		rs.close
		set rs = nothing
		psError = Err.Description
else
		psError = "One or more required properties (FileFullPath and/or FileInputName) not set"

  End If


End Function

Public Property Get Error()
	Error = psError
End Property


' ------------------------------------------------------------------------------
	Public Property Get ContentTypeOf(ByRef avKeyIndex)
		Dim lnIndex
		lnIndex = IndexOf(avKeyIndex)
		if lnIndex = -1 Then Exit Property
		ContentTypeOf = oFields(lnIndex).ContentType
	End Property

' ------------------------------------------------------------------------------
	Private Sub Class_Terminate()
		Dim lnIndex
		For lnIndex = 0 To nFieldCount - 1
			Set oFields(0) = Nothing
		Next
	End Sub
' ------------------------------------------------------------------------------
	Private Sub Class_Initialize()
		
		Dim lnBytes				' Bytes received from the client
		Dim lnByteCount			' Number of bytes received
		Dim lnStartPosition		' Position at which content begins
		Dim lnEndPosition		' Position at which content ends
		
		Dim loDic				' Contains properties of each
								' specific field
								' Local dictionary object(s) 
								' to be appended to class-scope
								' dictioary object.
								
		Dim lnBoundaryBytes		' Bytes contained within the current boundary
		Dim lnBoundaryStart		' Position at wich the current boundary begins
								' within the lnBytes binary data.
		Dim lnBoundaryEnd		' Position at wich the current boundary ends
								' within the lnBytes binary data.
		Dim lnDispositionPosition
		
		Dim lsFieldName			' Name of the current field being parsed from
								' Binary Data
		Dim lsFileName			' Name of the file within the current boundary
		Dim lnFileNamePosition	' Location of file name within current boundary
		Dim loField				' clsField Object
		Dim lsValue				' Value of the current field
		Dim lsContentType		' ContentType of the binary file (MIME Type)
		
		' Initialize Fields
		nFieldCount = 0
		ReDim oFields(-1)
		
		' Read the bytes (binary data) into memory	
		lnByteCount = Request.TotalBytes
		lnBytes = Request.BinaryRead(lnByteCount)
		
		'Get the lnBoundaryBytes
		lnStartPosition = 1
		lnEndPosition = InstrB(lnStartPosition, lnBytes, CStrB(vbCr))
		
		If lnEndPosition >= lnStartPosition Then
			lnBoundaryBytes = MidB(lnBytes, lnStartPosition, lnEndPosition - lnStartPosition)
		End If
		
		lnBoundaryStart = InstrB(1, lnBytes, lnBoundaryBytes)
		
		
		' Loop until the BoundaryBytes begin with "--"
		Do Until (lnBoundaryStart = InstrB(lnBytes, lnBoundaryBytes & CStrB("--")))
		
			' All data within this boundary is stored within a local dictionary
			' to be appended to the class-scope dictionary.
			
			ReDim Preserve oFields(nFieldCount)
			nFieldCount = nFieldCount + 1
			
			Set loField = New clsField

			lnDispositionPosition = InstrB(lnBoundaryStart, lnBytes, CStrB("Content-Disposition"))
			
			' Get an object name
			lnStartPosition = InstrB(lnDispositionPosition, lnBytes, CStrB("name=")) + 6
			lnEndPosition = InstrB(lnStartPosition, lnBytes, CStrB(""""))
			lsFieldName = CStrU(MidB(lnBytes, lnStartPosition, lnEndPosition - lnStartPosition))
			loField.FieldName = lsFieldName
			
			' Get the location fo the file name.
			lnFileNamePosition = InstrB(lnBoundaryStart, lnBytes, CStrB("filename="))
			lnBoundaryEnd = InstrB(lnEndPosition, lnBytes, lnBoundaryBytes)
			
			'Test if object is a file
			If Not lnFileNamePosition = 0 And lnFileNamePosition < lnBoundaryEnd Then
			
				' Parse Filename
				lnStartPosition = lnFileNamePosition + 10
				lnEndPosition =  InstrB(lnStartPosition, lnBytes, CStrB(""""))
				lsFileName = CStrU(MidB(lnBytes,lnStartPosition,lnEndPosition-lnStartPosition))
				loField.FileName = lsFileName				
				
				' Parse Content-Type
				lnStartPosition = InstrB(lnEndPosition,lnBytes,CStrB("Content-Type:")) + 14
				lnEndPosition = InstrB(lnStartPosition,lnBytes,CStrB(vbCr))
				lsContentType = CStrU(MidB(lnBytes,lnStartPosition,lnEndPosition-lnStartPosition))
				loField.ContentType = lsContentType

				' Parse Content
				lnStartPosition = lnEndPosition + 4
				lnEndPosition = InstrB(lnStartPosition,lnBytes,lnBoundaryBytes)-2
				lsValue = MidB(lnBytes,lnStartPosition,lnEndPosition-lnStartPosition)
				loField.BinaryData = lsValue & CStrB(vbNull)
				loField.Length = LenB(lsValue)
			Else

				' Parse Content
				lnStartPosition = InstrB(lnDispositionPosition, lnBytes, CStrB(vbCr)) + 4
				lnEndPosition = InstrB(lnStartPosition, lnBytes, lnBoundaryBytes) - 2
				lsValue = CStrU(MidB(lnBytes,lnStartPosition,lnEndPosition-lnStartPosition))
				loField.Value = lsValue
				loField.Length = Len(lsValue)
			End If

			Set oFields(UBound(oFields)) = loField

			'Loop to next object
			lnBoundaryStart = InstrB(lnBoundaryStart + LenB(lnBoundaryBytes), lnBytes, lnBoundaryBytes)
			
			Set loField = Nothing
			
		Loop

	End Sub
' ------------------------------------------------------------------------------
	Private Function CStrU(ByRef psByteString)
		Dim lnLength
		Dim lnPosition
		lnLength = LenB(psByteString)
		For lnPosition = 1 To lnLength
			CStrU = CStrU & Chr(AscB(MidB(psByteString, lnPosition, 1)))
		Next
	End Function
' ------------------------------------------------------------------------------
	Private Function CStrB(ByRef psUnicodeString)
		Dim lnLength
		Dim lnPosition
		lnLength = Len(psUnicodeString)
		For lnPosition = 1 To lnLength
			CStrB = CStrB & ChrB(AscB(Mid(psUnicodeString, lnPosition, 1)))
		Next
	End Function
' ------------------------------------------------------------------------------
End Class
' ------------------------------------------------------------------------------
%>

Code:

'get client file name without path
		sFileSplit = Split(o.FileNameOf("txtFile"), "\")
		sFile = sFileSplit(UBound(sFileSplit))
		rootPath = Server.MapPath(".") & "\"

		o.FileInputName = "txtFile"
		o.FileFullPath = rootPath & sFile
		o.Save

		If o.Error = "" Then
			response.write "Success. File saved to  " & o.FileFullPath & ". Demo Input = " & o.ValueOf("Demo")
 		Else
			response.write "Failed due to the following error: " & o.Error
	 	End If

		' Rename File
		Set fso = Server.CreateObject("Scripting.FileSystemObject")
			If fso.FileExists(o.FileFullPath) = True Then
				newFileName = Val_Rand3&"." & Right(sFile, 3)
				fso.CopyFile o.FileFullPath, rootPath & "..\Images\" & newFileName
				fso.DeleteFile(o.FileFullPath)
			End If
		Set fso = Nothing

 

You surely can put a restriction on the upload filesize, just write the uploaded file to a temporary location, read the size, if its over permissible limits, delete it and report the error to the user. But, I am unsure of the image dimension restriction, do you have any image manipulation library??