Child Menu 菜单选定界面

'****************************
'    Child Menu 菜单选定界面
'****************************
 Function fChildMenu$(m1$,m2$,m3$,m4$)
  k$=""
  sel%=0
  Cls
  While 1
   Screen 1,0
   If m1$<>"" Then
    Locate 6,1,0 :Print "1. ";m1$
   End If
   If m2$<>"" Then
    Locate 6,3,0 :Print "2. ";m2$
   End If
   If m3$<>"" Then
    Locate 6,5,0 :Print "3. ";m3$
   End If
   If m4$<>"" Then
    Locate 6,7,0 :Print "4. ";m4$;
   End If
   Locate 3,9,0:Print "";
   Screen 1,1
   Select k$
    Case Chr$(13)
     Beep ,,,0
     fChildMenu$=Mid$(Str$(sel%),2)
     Exit Function
    Case Chr$(27)
     If m1$<>"" Then
      Beep ,,,0
      fChildMenu$=Chr$(27)
      Exit Function
     End If
    Case Chr$(49)
     If m1$<>"" Then
      Beep ,,,0
      Locate 6,1,0 :Print "1. ";m1$
      sel%=1
     End If
    Case Chr$(50)
     If m2$<>"" Then
      Beep ,,,0
      Locate 6,3,0 :Print "2. ";m2$
      sel%=2
     End If
    Case Chr$(51)
     If m3$<>"" Then
      Beep ,,,0
      Locate 6,5,0 :Print "3. ";m3$
      sel%=3
     End If
    Case Chr$(52)
     If m4$<>"" Then
      Beep ,,,0
      Locate 6,7,0 :Print "4. ";m4$;
      sel%=4
     End If
   End Select

   k$=Input$(1)
  Wend
 End Function
'*****************************
'         main
'*****************************

 BEEP
 KEY 5,CHR$(28)
 Key 6,Chr$(29)
 Key 7,Chr$(30)
 Key 8,Chr$(31)
 KEY 30,CHR$(27) 'M1 :ESC键退出键

MAIN:
      
       Cls
       Screen 1,0
       locate 3,5:print "主程序界面"
       While 1
          k$=Input$(1)
          If k$=chr$(27) Then
             GoTo ERRCOMM
          Else
             s$=fChildMenu$("aaaaa","bbbbb","ccccc","")
             Cls
             If s$=chr$(27) Then
             Print " 退出 "
             End If
             Screen 1,0
             print s$
          End If
       Wend
ERRCOMM:
 Cls
 Beep 8
 'Print "操作错误:"
 'Print
 'Print "按任意键退出";
 'Wait 0,1
 'k$=Input$(1)
 End