function Left(str, n){
	if (n <= 0)
	    return "";
	else if (n > String(str).length)
	    return str;
	else
	    return String(str).substring(0,n);
}

function Right(str, n){
    if (n <= 0)
       return "";
    else if (n > String(str).length)
       return str;
    else {
       var iLen = String(str).length;
       return String(str).substring(iLen, iLen - n);
    }
}


function validatechar(field) {

var valid = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
var ok = "yes";
var temp;

for (var i=0; i<field.value.length; i++) {
	temp = "" + field.value.substring(i, i+1);
	if (valid.indexOf(temp) == "-1") ok = "no";
	}
if (ok == "no") {
	alert("Invalid entry!  Only characters are accepted!");
	field.focus();
	field.select();
	return false;
   	}
return true;
}

function validatenumber(field) {

var valid = "0123456789";
var ok = "yes";
var temp;

for (var i=0; i<field.value.length; i++) {
	temp = "" + field.value.substring(i, i+1);
	if (valid.indexOf(temp) == "-1") ok = "no";
	}
if (ok == "no") {
	alert("Invalid entry!  Only Numbers are accepted!");
	field.focus();
	field.select();
	return false;
   	}
return true;
}

function validateemail(field)
{

var email;
email = field.value;
emailAt = field.value.indexOf("@");
emailDot = field.value.indexOf(".");

if (emailAt == -1)
{
	alert("Not a valid e-mail address.  Please input a valid email address.")
	field.focus();
	field.select();
	return false;
	}

if (emailDot == -1)
{
	alert("Not a valid e-mail address.  Please input a valid email address.")
	field.focus();
	field.select();
	return false;
	}

if (email.value =="") {
	return false;
	}

return true;

}

function validate() {

if (!validatechar(document.forms.customerdetails.FirstName)){return false;}

if (document.forms.customerdetails.FirstName.value == "")
	{
	alert("Please enter your first name.");
	document.forms.customerdetails.FirstName.value="";
	document.forms.customerdetails.FirstName.focus();
	return false;
	}

if (!validatechar(document.forms.customerdetails.LastName)){return false;}

if (document.forms.customerdetails.LastName.value == "")
	{
	alert("Please enter your last name.");
	document.forms.customerdetails.LastName.value="";
	document.forms.customerdetails.LastName.focus();
	return false;
	}

if (!validateemail(document.forms.customerdetails.Email)){return false;}

if (document.forms.customerdetails.Email.value == "")
	{
	alert("Please enter your email address.");
	document.forms.customerdetails.Email.value="";
	document.forms.customerdetails.Email.focus();
	return false;
	}
}