Data type mismatch error

[nigelbloomy]

I am getting a datatype mismatch error on the final line of this code. Can anyone see why?

Sub Rollup()    Dim rsQueryResults, rsCalculate, rsRollInto, rsBOMTable As DAO.Recordset
    Dim stQuery, strSQL, stParent As String
    Dim iLevel, i As Integer
    Dim dbRollup As Double
    
    'Find the highest level number in BOM Table and put it into a variable called iLevel
    stQuery = "SELECT Max([BOM Table].Level) AS MaxOfLevel FROM [BOM Table];"
    Set rsQueryResults = CurrentDb.OpenRecordset(stQuery)
    iLevel = rsQueryResults!MaxofLevel
    Debug.Print "iLevel="; iLevel
    
    Set rsQueryResults = Nothing
    Set rsBOMTable = CurrentDb.OpenRecordset("BOM Table", dbOpenDynaset)
    
    'Filter the BOM Table to show only the parts at the highest level
    stQuery = "SELECT [BOM Table].Parent_Number, [BOM Table].Item_Number, " & _
            "[BOM Table].Level, [BOM Table].Quantity_Per, [BOM Table].Labor_Cost " & _
            "FROM [BOM Table] WHERE ((([BOM Table].Level)='" & iLevel & "'));"
    
    
    Set rsCalculate = CurrentDb.OpenRecordset(stQuery)

[nigelbloomy]

Fixed. For some reason the single quotes around " & iLevel & " in the WHERE section was messing up the query. I have had to use the single quotes before to get the queries to work, so I don't know why they messed up this query.

Does someone know the rules about when to use single quotes and when not to?