function check_phone_number() {

  /* Set whether the user should use a -, a space, or one long number without divisions.
     Use the following values to set:
	 1 = Use - (i.e 123-456-7890)
	 2 = Use a space (i.e. 123 456 7890)
	 3 = Use none (i.e. 1234567890)
  */	 
  /*var num_division = 3;
  
  if (document.getElementById && document.createTextNode) {	
    
	var phone_num_OK = false; 
	var the_delim = "";
	var the_ph_test = "";
	var ph_err_msg ="";
    var the_phone_num = document.getElementById("phone_number").value;
	
	if (num_division == 3) {
		the_delim = "";
		the_ph_test = /^[0-9]{10}/;
	    phone_num_OK = the_ph_test.test(the_phone_num);
	}
	
	else if (num_division == 2) {
		the_delim = " ";
		the_ph_test = /^[0-9]{3} [0-9]{3} [0-9]{4}$/;
	    phone_num_OK = the_ph_test.test(the_phone_num);
	}
	else if (num_division == 1) {
		the_delim = "-";
		the_ph_test = /^[0-9]{3}-[0-9]{3}-[0-9]{4}$/;
	   	phone_num_OK = the_ph_test.test(the_phone_num);
	}
	else {
		window.alert("Cannot validate.");
		return false;	
	}
	
    if (phone_num_OK) {
	  return true;	
	}
	else {
	    ph_err_msg="An invalid phone number was entered. Valid format is:\n123"+the_delim+"456"+the_delim+"7890";
	    window.alert(ph_err_msg);
	    return false;
	}
	
  }*/
  
}

// 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 = 5;

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 ValidateForm(Phone){
	//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
 }