regular expression is not working

[eluser]samitrimal[/eluser]
Hi i have a problem in using dollor sign in my regular expression . When i dont use dollar sign it works fine.Here is a code

Code:

$pattern="/^[^0-9][0-5a-zA-Z]{1,}([a-zA-Z0-9_|-])*$/";
if (preg_match($pattern, "a12-|", $matches)) {
  echo "Match was found <br />";
  echo $matches[0];
}
else{
  echo "Pattern does not match";
}

The error occours when i use dollor sign.

Code:

$pattern="/^[^0-9][0-5a-zA-Z]{1,}([a-zA-Z0-9_|-$])*$/";
if (preg_match($pattern, "a12-|$", $matches)) {
  echo "Match was found <br />";
  echo $matches[0];
}
else{
  echo "Pattern does not match";
}

I encountered the following error

Code:

Warning: preg_match() [function.preg-match]: Compilation failed: range out of order in character class at offset 36 in E:\wamp\www\graph\testpractice\php\regex\pregmath.php on line 3

need help to solve this problem