a little something from the javascript guide
Code:
charAt 
Method. Returns the character at the specified index.

Syntax 
stringName.charAt(index)
Parameters 
stringName is any string or a property of an existing object.
index is any integer from zero to stringName.length - 1, or a 
property of an existing object.

Implemented in 
Navigator 2.0

Description 
Characters in a string are indexed from left to right. 
The index of the first character is zero, and the index
 of the last character is stringName.length - 1.
 If the index you supply is out of range, 
JavaScript returns an empty string.

Examples 
The following example displays characters at different 
locations in the string "Brave new world":

var anyString="Brave new world"
document.write("The character at index 0 is " + anyString.charAt(0))
document.write("The character at index 1 is " + anyString.charAt(1))
document.write("The character at index 2 is " + anyString.charAt(2))
document.write("The character at index 3 is " + anyString.charAt(3))
document.write("The character at index 4 is " + anyString.charAt(4))