Java Array Creation error

I've got some java scripting to assist with pulling up images, and for one section, I need to strip out leading 0's that are on the screen to find the correct image. I found some great code on the web, but Lawson is screaming at the commented-out line where I declare the array. Is there a way to do this that Design Studio approves of?
Here's the code I have:
function removeLeadingZeros(str)
{
 if (str == null)
 {
  return null;
 }
// char[] chars = str.toCharArray();
 index = 0;
 for (; index < str.length();index++)
 {
  if (chars[index] != '0')
  {
   break;
  }
 }
 return (index == 0) ? str :str.substring(index);
}