我做网页时出错：显示字样为
Microsoft VBScript 运行时错误 (0x800A0005)
无效的过程调用或参数: 'LeftB'
/www/毕业设计/admin/telephone_add_picture2.asp, 第 19 行
          Dim formData,formsize
        formsize=Request.TotalBytes           
        formdata=Request.BinaryRead(formsize) 
        Dim filepath,contentType,fileimage,filesize
    Dim bncrlf,divider,dataStart,dataEnd,dataLen,temp
第十八行: bncrlf=ChrB(13) & ChrB(10)                                        
         divider=LeftB(formData,CInt(InstrB(formdata,bncrlf))-1)             
    
      datastart=InstrB(formdata,bncrlf)+59  
                                 
  dataend=InstrB(datastart,formdata,bncrlf)-2   
      
dataLen=dataend-datastart+1                                     
    
filepath=MidB(formdata,datastart,datalen)                        
    
filepath=BinaryToString(filepath)  
         temp=dataend                                                          

datastart=temp+18                                                
   
dataend=InstrB(datastart,formdata,bncrlf & bncrlf)-1                 
dataLen=dataend-datastart+1                                           
contentType=MidB(formdata,datastart,datalen)                       
contentType=BinaryToString(contentType)                                
temp=dataend
datastart=dataend+5                                                   
dataend=InstrB(datastart,formdata,divider)-3                          
dataLen=dataend-datastart+1                                          
fileimage=MidB(formdata,datastart,datalen)                      
filesize=Lenb(fileimage)
       
请问这是什么原因，我得怎么改  谢谢帮忙！！！