my first spot is that "$string" bit, should you not just use $string (ie no quotes)?
I'm not sure the procedure is correct (i could be wrong i'm fairly new to php).
:
open file, get a line, do the ereg replace, write the line, get next line, do the ereg, write line etc until you have done all of the lines, then fclose ($file).
something like this maybe ??
$filename = "Sp200103.wet";
$openb = fopen ($filename, "w+");
$string = file ($filename);
for ($n = 0; $n < count($string);
$n++)
{
$string[$i] = eregi_replace (",", " ", $string[$i]);
fwrite ($open, "$string[$i]");
}
fclose ($openb);
Not sure if it works, i think it should do, give it a go & let me know what happens
Jamie