/**
 * DHTML validation scripts. 
 * Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */

var digits = "0123456789";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldPhoneChars = phoneNumberDelimiters + "+";
// Minimum no of digits in an international phone no.
var minDigitsInIPhoneNumber = 10;

function echeck(email,displayName) {
	var at="@";
	var dot=".";
	var lat=email.indexOf(at);
	var lstr=email.length;
	var ldot=email.indexOf(dot);
	if (email.indexOf(at)==-1){
	   alert("Invalid " + displayName);
	   return false;
	}

	if (email.indexOf(at)==-1 || email.indexOf(at)==0 || email.indexOf(at)==lstr){
	   alert("Invalid " + displayName);
	   return false;
	}

	if (email.indexOf(dot)==-1 || email.indexOf(dot)==0 || email.indexOf(dot)==lstr){
	    alert("Invalid " + displayName);
	    return false;
	}

	 if (email.indexOf(at,(lat+1))!=-1){
	    alert("Invalid " + displayName);
	    return false;
	 }

	 if (email.substring(lat-1,lat)==dot || email.substring(lat+1,lat+2)==dot){
	    alert("Invalid " + displayName);
	    return false;
	 }

	 if (email.indexOf(dot,(lat+2))==-1){
	    alert("Invalid " + displayName);
	    return false;
	 }
	
	 if (email.indexOf(" ")!=-1){
	    alert("Invalid " + displayName);
	    return false;
	 }
	 return true;				
}

function isInteger(s) {
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag) {
    var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++) {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function checkInternationalPhone(strPhone) {
	s=stripCharsInBag(strPhone,validWorldPhoneChars);
	return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}

function validateText(inputField, displayName) {
	if ((inputField.value==null)||(inputField.value=="")) {
		alert("Please enter your " + displayName);
		inputField.focus();
		return false;
	}
	return true;
 }

function validateEmail(email, displayName) {
	if ((email.value==null)||(email.value=="")) {
		alert("Please enter your " + displayName);
		email.focus();
		return false;
	}
	if (echeck(email.value, displayName)==false) {
		email.value="";
		email.focus();
		return false;
	}
	return true;
 }

function validatePhone(phone, displayName){
	if ((phone.value==null)||(phone.value=="")){
		alert("Please enter your " + displayName);
		phone.focus();
		return false;
	}
	if (checkInternationalPhone(phone.value)==false){
		alert("Please enter a valid " + displayName);
		phone.value="";
		phone.focus();
		return false;
	}
	return true;
 }