var digits = "0123456789";
var phoneNumberDelimiters = "()- ";
var validWorldPhoneChars = phoneNumberDelimiters + "+";
var minDigitsInIPhoneNumber = 11;

//-------------------------------------------------------------------	
function isInteger(s)

{
	 var i;
	for (i = 0; i < s.length; i++)
		{
		var c = s.charAt(i);
			if (((c < "0") || (c > "9"))) return false;
		}
	return true;
}	

//------------------------------------------------------------------

function isText(s)
{
	var i;
	var u = s.toUpperCase();
	for (i = 0; i < u.length; i++)
		{
		var c = u.charAt(i);
			if (((c < "A") || (c > "Z"))) return false;
		}
	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 validate_email(field,alerttxt)
{
	with (field)
	{
	apos=value.indexOf("@")
	dotpos=value.lastIndexOf(".")
		if (apos<1||dotpos-apos<2)
			{alert(alerttxt);return false}
		else {return true}
	}
}
	
//----------------------------------------------------------------
	
function Validate_name(field,alerttxt)
{
	with (field)
	{
	v = value;
	s=stripCharsInBag(v,".' ")
	i = isText(s)
		if (i==false || s.length < 4)
			{alert(alerttxt);return false}
		else {return true}	
	}
}

//---------------------------------------------------
		
function validate_phone(field,alerttxt)
{
	with (field)
	{
	strPhone = value;
	s=stripCharsInBag(strPhone,validWorldPhoneChars);
	i=isInteger(s)
		if (i==false || s.length < 11)
			{alert(alerttxt);return false}
		else {return true}
	}	
}

//-----------------------------------------------------
	
function validate_form(thisform)
{
	with (thisform)
	{
		if (validate_email(Client_mail,"Please enter a valid e-mail address")==false)
			{Client_mail.focus();return false}
					
		if (Validate_name(Client_name,"Name must be four letters or more")==false)
			{Client_name.focus();return false}
			
		if (validate_phone(Contact_number,"Please enter a valid phone number")==false)
			{Contact_number.focus();return false}
			
		
	}
}