To shorten your string of chars work you can use the ascii method to include all numbers, lower case letters and upper case letters.
_________________________________________________________
char [] Chars = new char [63];
int counter = 0;
for (int i = 48 ; i < 123 ; i++)
{
counter++;
//ignore all other chars
if (i == 58)
i = 65;
if (i == 91)
i = 97;
/*
//remove the comments if you want remove all vowels
//add and remove vowels as necessary
char ch = (char) i;
if (ch == 'a' || ch == 'e' || ch == 'o' || ch == 'u' || ch == 'i' || ch == 'y' || ch == 'A' || ch == 'E' || ch == 'O' || ch == 'U' || ch == 'I' || ch == 'Y')
counter--;
else */
Chars [counter] = (char) i;
}
________________________________________________________
Just something you might want to use for future as well.
B.G