/*
 * This script and many more are available free online at The JavaScript Source!!
 * http://javascript.internet.com Created by: Cyanide_7 |
 */

var isNN = ( navigator.appName.indexOf ( "Netscape" ) != -1 ) ;

function autoTab ( input, len, e ) {
	var keyCode = ( isNN ) ? e.which : e.keyCode ;
	var filter = ( isNN ) ? [0,8,9] : [0,8,9,16,17,18,37,38,39,40,46] ;
	if ( input.value.length >= len && !containsElement ( filter, keyCode )) {
		input.value = input.value.slice ( 0, len ) ;
		input.form[ (getIndex ( input ) +1 ) %input.form.length].focus();
	}

	function containsElement(arr, ele) {
	var found = false, index = 0 ;
	while ( !found && index < arr.length )
		if ( arr[index] == ele ) {
			found = true ;
		} else {
			index++ ;
		}
		return found;
	}

	function getIndex ( input ) {
	var index = -1, i = 0, found = false ;
	while ( i < input.form.length && index == -1 )
		if ( input.form[i] == input ) {
			index = i ;
		} else {
			i++ ;
		}
		return index ;
	}
	return true ;
}