Emmanuel,
I see both John and Colin have given you good suggestions. Just to add something, you'll need to make sure you account for the indexing scheme when you use SEEK or LOCATE. For example, if you're using VAL(MyField) as the index expression, SEEK(3) will work while SEEK("3") will not. To make sure an expression is optimizable, use LOCATE FOR VAL(MyField)=3. LOCATE FOR MyField="3" will work but won't be optimized.
>I need an index with the following secuence:
>
>"1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" ...
>
>the actual indexing method will do it like:
>
>"1" "11" "12" "2" "3" ...
>
>of course I'm talking about text data with numeric values