Field validation

[Brian Seavers <brian at bsweb dot co dot uk>]

Hi everyone

This MUST have been covered many times, but I haven't been able to 
find it through the archives.
I'm looking for simple editfield validation, i.e reject 
non-alphanumeric characters (and allow spaces !) as they are typed in 
an editfield.
I have placed the following code in the 'TextChange' event of the editfield :

  dim txt as string

  txt="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890 "

  if instr(1,txt,mid(me.text,me.selstart,1))<1 then
    me.text=replace(me.text,mid(me.text,me.selstart,1),"")
    me.selstart=me.selstart-1
  end if

Now... this IS working, but it is visibly slow (can see the 'replace' 
happen on my iMac 400 DVSE,[compiled!])...
There must be a neater way of doing this ! Any ideas ?

Thanks

Brian
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