>Sir, I have this line of code
>
>

>index on substr(alltrim(code2),1,7) tag xydg
>

>
>it displays this error message
>
>Error building for key index "c:\windows\temp\0001qlnd0098.cdx" tag "xydg"
>
>how to overcome this

Is it possible that code2 starts with spaces?

Try removing alltrim function, e.g.

index on left(code2, 7) tag first7chrs