Issue with Kirupa Dup MC

dupMovie =  function ()  { 
for (i=0;  i<50;  i++)  { 
photo.duplicateMovieClip("photo"+i,  i, {_x:125});
with (eval("photo"+i))  {
}
}
};
dupMovie();

I changed the code a bit because I would like it to work like this…If I put my mc (photo) in the center of the stage, it would creat dups every 125 pixels. But this script only makes one duplicate, I must have done something to mess it up. Idealy I would like to have the mc create dups in both directions; x and -x. Can anyone help me out, it would be great - thanks!