Help In Program

i have a program which should give the out like this
XAPIALTMKT20010829105525.TXT

but its giving the output = 'X'
which is just the first initial...how
can i get this...

if i don't write the @filename=....
only then its giving the output..but i want to store it in the
varable..how can i do that
================================
declare
@v datetime ,
@filename varchar

select @v=getdate()
select @filename='XAPIALTMKT'
+CONVERT(varchar, @v, 112)
+SUBSTRING(CONVERT(varchar, @v, 108), 1, 2)
+SUBSTRING(CONVERT(varchar, @v, 108), 4, 2)
+SUBSTRING(CONVERT(varchar, @v, 108), 7, 2)
+'.TXT'

print @filename
================================================

thanks,
Harish