function invalidEmail(textObj)
{
	if (textObj.value.length >0)
	{
		at_loc = textObj.value.indexOf("@");
		dot_loc = textObj.value.indexOf(".", at_loc);	
		comma = textObj.value.indexOf(",");	
		spaces = textObj.value.indexOf(" ");	
		last_dot = textObj.value.lastIndexOf(".") + 1;	
		len = textObj.value.length;
	    if ((at_loc > 0) && (dot_loc > (at_loc + 1)) &&
		    (comma == -1) && (spaces == -1) &&
            (len - last_dot >= 2) && (len - last_dot <= 3))
			return false;
		else
			return true;
	}
}

function emptyField(textObj)
{	
	if (textObj.value.length == 0) return true;
	for (var i = 0; i<textObj.value.length; ++i)
	{ 
		var ch = textObj.value.charAt(i);
		if (ch != ' ' && ch != '\t') return false;
	}
	return true;
}

function validateContactForm(formObj)
{
	if (emptyField(formObj.name))
	{
		alert("Please enter your Name.");
		selectElement(formObj.name);
		return false;
	}
	
	if (emptyField(formObj.email))
	{
		alert("Please enter Email.");
		selectElement(formObj.email);
		return false;
	}
	else if (invalidEmail(formObj.email))
	{
		alert("Invalid Email. Please enter a valid email address");
		selectElement(formObj.email);
		return false;
	}
	if (emptyField(formObj.tel))
	{
		alert("Please enter your Telephone Number.");
		selectElement(formObj.tel);
		return false;
	}
}
function validateCatalogueForm(formObj){
	
	if (emptyField(formObj.firstname))
	{
		alert("Please enter your First Name.");
		selectElement(formObj.firstname);
		return false;
	}
	if (emptyField(formObj.lastname))
	{
		alert("Please enter your Last Name.");
		selectElement(formObj.lastname);
		return false;
	}
	if (emptyField(formObj.email))
	{
		alert("Please enter Email.");
		selectElement(formObj.email);
		return false;
	}
	else if (invalidEmail(formObj.email))
	{
		alert("Invalid Email. Please enter a valid email address");
		selectElement(formObj.email);
		return false;
	}
	if (emptyField(formObj.address1))
	{
		alert("Please enter your Full Address.");
		selectElement(formObj.address1);
		return false;
	}
	/*if (emptyField(formObj.address2))
	{
		alert("Please enter your Full Address.");
		selectElement(formObj.address2);
		return false;
	}
	if (emptyField(formObj.address3))
	{
		alert("Please enter your Full Address.");
		selectElement(formObj.address3);
		return false;
	}
	*/
	if (emptyField(formObj.postaltown))
	{
		alert("Please enter your Postal Town.");
		selectElement(formObj.posttown);
		return false;
	}
	if (emptyField(formObj.county))
	{
		alert("Please enter your County.");
		selectElement(formObj.county);
		return false;
	}
	if (emptyField(formObj.postcode))
	{
		alert("Please enter your Post Code.");
		selectElement(formObj.postcode);
		return false;
	}
}
function selectElement(elem)
{
	if (elem!=null)
	{
		var tag = elem.tagName.toUpperCase();
		if (tag =="INPUT" || tag == "TEXTAREA")
			elem.select();
		elem.focus();
	}
}
function changeFieldValue(fieldname,newvalue){
	//alert(fieldname+".value= "+newvalue);
	fieldname.value=newvalue;
}