xml格式获取值

function getkeyvalue(s_keyname,s_keystr)
s_keybegin="<"+s_keyname+">"
s_keyend="</"+s_keyname+">"
s_i_begin=instr(s_keystr,s_keybegin)
s_i_end=instr(s_keystr,s_keyend)
if s_i_end<=s_i_begin+len(s_keybegin) then
getkeyvalue=""
exit function
else
getkeyvalue=mid(s_keystr,s_i_begin+len(s_keybegin),s_i_end-s_i_begin-len(s_keybegin))
exit function
end if
end function
function setkeyvalue(s_keyname,s_keystr,s_keyvalue)
if isnull(s_keyvalue) then
setkeyvalue=s_keystr
exit function
end if
s_keybegin="<"+s_keyname+">"
s_keyend="</"+s_keyname+">"
s_i_begin=instr(s_keystr,s_keybegin)
s_i_end=instr(s_keystr,s_keyend)
if s_i_end<=s_i_begin+len(s_keybegin) then
setkeyvalue=s_keystr+s_keybegin+s_keyvalue+s_keyend
exit function
else
setkeyvalue=mid(s_keystr,1,s_i_begin-1)+s_keybegin+s_keyvalue+s_keyend+mid(s_keystr,s_i_end+len(s_keyend))
exit function
end if
end function