换成图片居然不行,哪位高手可以教一下,多谢

换成图片居然不行,谁可以教一下,谢谢
<!--#include   file= '../conn.asp '   -->
<%
dim   pre,icount
dim   sql,rs
dim   preImg1,preImg2

pre= "&nbsp;&nbsp;&nbsp;&nbsp; "
icount=0
'preImg1= " <img   src= '../images/add.gif '>   "
'preImg2= " <img   src= '../images/dec.gif '>   "
preImg1= "+   "
preImg2= "-   "

sql= "select   id,forum_xmmc,upid   from   forum_type   order   by   flag,upid "
set   rs=server.createObject( "adodb.recordset ")
rs.open   sql,conn,1,1
if   not   rs.eof   and   not   rs.bof   then
        do   while   not   rs.eof
if   icount=0   then   Response.Write   " <div> "
                if   rs( "upid ")=0   then
                        response.write   " </div> <div   onclick= " "javascript:if(div "&rs(0)& ".style.display== ' '){div "&rs(0)& ".style.display= 'none ';span "&rs(0)& ".innerHTML= ' "&preImg1& " ';}else{div "&rs(0)& ".style.display= ' ';span "&rs(0)& ".innerHTML= ' "&preImg2& " ';} " "> <span   id= " "span "&rs(0)& " " "> "&preImg1& " </span> "&rs(1)& " </div> <div   id= " "div "&rs(0)& " " "   style= " "display:none; " "> "
                else                        
                Response.Write   pre&rs(1)& " <br/> "
                end   if
if   icount=rs.recordcount   then   Response.Write( " </div> ")
      icount=icount+1
                      rs.movenext
        loop
else
        Response.Write   "没有任何栏目 "
end   if
rs.close
set   rs=nothing
%>


我如果想把那个
preImg1= "+   "
preImg2= "-   "

换成:
preImg1= " <img   src= '../images/add.gif '>   "
preImg2= " <img   src= '../images/dec.gif '>   "

换成图片却居然不行!   谁可以教一下,谢谢!

------解决方案--------------------
preImg1= " <img src=../images/add.gif> "
preImg2= " <img src=../images/dec.gif> "