// Declaring required variables
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 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 trim(s)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not a whitespace, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (c != " ") returnString += c;
    }
    return returnString;
}
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){
var bracket=3
strPhone=trim(strPhone)
if(strPhone.indexOf("+")>1) return false
if(strPhone.indexOf("-")!=-1)bracket=bracket+1
if(strPhone.indexOf("(")!=-1 && strPhone.indexOf("(")>bracket)return false
var brchr=strPhone.indexOf("(")
if(strPhone.indexOf("(")!=-1 && strPhone.charAt(brchr+2)!=")")return false
if(strPhone.indexOf("(")==-1 && strPhone.indexOf(")")!=-1)return false
s=stripCharsInBag(strPhone,validWorldPhoneChars);
return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}
function emailcheck(str){
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
	   return false
	}
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   return false
	}
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    return false
	}
	if (str.indexOf(at,(lat+1))!=-1){
	   return false
	}
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	   return false
	}
	if (str.indexOf(dot,(lat+2))==-1){
	   return false
	}
	if (str.indexOf(" ")!=-1){
	   return false
	}
	return true					
}
function checkthis(){
	if(document.registerform.email.value!=""){
		document.registerform.emailalerts.checked=true;
	}else{
		document.registerform.emailalerts.checked=false;
	}
	
	if(document.registerform.mobilenumber.value!=""){
		document.registerform.textalerts.checked=true;
	}else{
		document.registerform.textalerts.checked=false;
	}
}
function boxcheck(){
	if(document.registerform.emailalerts.checked==false){
		document.registerform.email.value="";
	}
	if(document.registerform.textalerts.checked==false){
		document.registerform.mobilenumber.value="";
		document.registerform.provider.value="NONE";
	}
}
function verify(){
	if(document.registerform.textalerts.checked==true){
		if(document.registerform.mobilenumber.value=="" || document.registerform.provider.value=="NONE"){
			alert('You must enter a phone number and select your mobile provider if signing up for text alerts');
			if(document.registerform.mobilenumber.value==""){
				document.registerform.mobilenumber.focus();
			}else{
				document.registerform.provider.focus();
			}
			return false;
		}
		if(document.registerform.mobilenumber.value!=""){
			if(checkInternationalPhone(document.registerform.mobilenumber.value)==false){
				alert('Please enter a valid phone number excluding any special characters like ( and )');
				document.registerform.mobilenumber.focus();
				return false;
			}
			
		}
	}
	if(document.registerform.emailalerts.checked==true){
		if(document.registerform.email.value==""){
			alert('You must enter an email address if you wish to receive email alerts');
			document.registerform.email.focus();
			return false;
		}else{
			if(!emailcheck(document.registerform.email.value)){
				alert('You must enter a valid email address if you wish to receive email alerts');
				document.registerform.email.focus();
				return false;
			}
		}
		
	}
	if(document.registerform.emailalerts.checked==false && document.registerform.textalerts.checked==false){
		alert('You must enter an email address or mobile number to sign up for this service');
		return false;
	}
	if(document.registerform.security_code.value==""){
		alert('You must enter the security code to proceed');
		document.registerform.security_code.focus();
		return false;
	}
	if(document.registerform.agreeterms.checked==false){
		alert('You must agree to the eLert Terms of Service and Disclaimer to sign up for this service');
		return false;
	}
	return true;
}