Palindrome testing program. String error

[Hotsawwce]

I keep getting an error saying: Exception in thread"main" java.lang.StringIndexOutOfBoundsException: String index out of range: 109
at java.lang.String.charAt(unknow source)
at test.main(test.java:23)

Here is my code:

import java.util.Scanner;
public class test
{

	public static void main (String[] args)
	{

		
		Scanner input = new Scanner(System.in);
		
		
			String palTest = input.next();
			
	

		int test = palTest.length()-1;
		char firstChar, lastChar;
		char first = palTest.charAt(0);
		char last = palTest.charAt(test);
		while (first<last)
		{
		
		firstChar = palTest.charAt(first);
		lastChar = palTest.charAt(last);
		
		if(firstChar == lastChar)
		{
		first++;
		last--;
		}
		
		}
		System.out.println();
		if (first < last)
		System.out.println("k");
		else 
		System.out.println("wtf");
		}
		}

I don't seem to get the problem if the string is only one char long. But I can't seem to find my mistake.


*edit* It seems to work with numbers only actually >_>

[arieltal]

 firstChar = palTest.charAt(first);
        lastChar = palTest.charAt(last);

here you use first and last, which are CHARS, not int location in the string..
think the problem starts here.

[SJF]

As arieltal pointed out:
String.charAt(int i) NOT String.charAt(char c) ..... Java is doing an implicit typecast of char to int.... (int)'n' = 110