//phone check

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 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 ValidateForm(){
	var Phone=document.frmSample.txtPhone
	
	if ((Phone.value==null)||(Phone.value=="")){
		alert("Please Enter your Phone Number")
		Phone.focus()
		return false
	}
	if (checkInternationalPhone(Phone.value)==false){
		alert("Please Enter a Valid Phone Number")
		Phone.value=""
		Phone.focus()
		return false
	}
	return true
 }

//email checker

function isValidEmail(str) {
   return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
 
}

//main function 

function checkForm() {

	//alert ("this is working");
		

	if (document.getElementById('firstName').value == 0){
	
		alert ("Please enter your first name");
		document.getElementById('firstName').focus();
		return false;
	
	}
	
	if (document.getElementById('lastName').value == 0){
	
		alert ("Please enter your last name");
		document.getElementById('lastName').focus();
		return false;
	
	}
	
	if (document.getElementById('phoneNumber').value == 0){
	
		alert ("Please enter your phone number");
		document.getElementById('phoneNumber').focus();
		return false;
	
	}
	
	if (checkInternationalPhone(document.getElementById('phoneNumber').value)==false){
		alert("Please Enter a Valid Phone Number")
		document.getElementById('phoneNumber').value=""
		document.getElementById('phoneNumber').focus()
		return false
	}
	
	if (document.getElementById('email').value == 0){
	
		alert ("Please enter your Email");
		document.getElementById('email').focus();
		return false;
	
	}
	
	else {
	
		if (isValidEmail(document.getElementById('email').value)) {
		
			//alert ("works");
		}
		else {
			alert ("Please enter a Valid email address.");
			document.getElementById('email').focus();
			return false;
		}
		
	
	}

	return true;

}