var isIE = document.all?true:false;
var isNS = document.layers?true:false;

function e164Inversare(inputField, outputField, event) {

	if (validateInput(event)) {

		// strip whitespace and shorten string to 11 characters
		var input = inputField.value.replace(/[ ]/g,'').substring(0,14);
		var output = "";

		for (i = input.length-1; i >= 0; i--) {
			// dot seperation
			if (output.length > 0) output += "." + input.charAt(i);
			else output += input.charAt(i);
		}
		outputField.value = output + ".0.4.e164.arpa";
	}

	else return false;
}

function validateInput(event) {
	var key;
	var keychar;
	if (window.event) key = window.event.keyCode;
	else if (event) key = event.which;
	else return true;

	keychar = String.fromCharCode(key);

	// control keys
	if ((key==null) || (key==0) || (key==8) || (key==27)) return true;

	// numbers and whitespace
	else if ((("0123456789 ").indexOf(keychar) > -1)) return true;

	else return false;
}