Ok, thanks to all.
The trouble was cause by the "stretching" of strings in the loop.
Now I use the same logic, but without stretching the sting in the array.
I do a test to put the more appropriate char in the array, so there is always only one char by elements in the array.
Now the scanning was fast and "linear" in processing time.
You have help me to find the solution...
Many Thanks :-)
If we exchange an apple, we both get an apple.
But if we exchange an idea, we both get 2 ideas, cool...Gérald Santerre
Independant programmer - internet or intranet stuff - always looking for contracts big or small :)
http://www.siteintranet.qc.ca 
