VB6为什么生成EXE文件后，调用EXECL的语句用不了显示错误

Dim ExlApp As Object
Dim ExlBook As Object
Dim ExlSheet As Object

Private Sub Command1_Click()
 Set ExlApp = CreateObject("Excel.Application") '创建Excel的应用程序实例
 Set ExlBook = ExlApp.Workbooks.Add '创建Excel的工作簿
 Set ExlSheet = ExlBook.Worksheets(1) '创建Excel的一张表
 ExlSheet.Range("A:G").Font.Size = 9         '设置A到G列的字号
 ExlSheet.Range("A:G").Font.Name = "宋体"    'A到G列字体
 ExlSheet.Range("A:A").RowHeight = 24        'A到A列行高
 ExlSheet.Range("A1:G1").Font.Name = "黑体"  '首行字体
 ExlSheet.Range("A1:G1").Font.Bold = True    '首行加粗
 ExlSheet.Rows.HorizontalAlignment = xlVAlignCenter  '设置水平居中
 ExlSheet.Rows(1).RowHeight = 24         '第1行的行高=24
 ExlSheet.Cells(1, 1).Value = "单　位"
 ExlApp.Visible = True '显示Excel
 Set ExlSheet = Nothing
 Set ExlBook = Nothing
 Set ExlApp = Nothing
End Sub