function validatebuyproduct(){
	if (document.addtocart.productquantity.value == '')
	{
		alert ('Please enter a value for quantity.');
		return false;
	}
	else
	{
		if	(isNaN(document.addtocart.productquantity.value)) 
		{
			alert("Please enter a numerical value for the quantity.");
			return false;
		}	
		else
			document.addtocart.submit();
	}
}

function IsEmailValid()
	{
		var EmailOk  = false;
		var Temp     = document.contactdetails.clientemail;
		var AtSym    = Temp.value.indexOf('@');
		var Period   = Temp.value.lastIndexOf('.');
		var Space    = Temp.value.indexOf(' ');
		var Length   = Temp.value.length - 1; 
		if ((AtSym < 1) || (Period <= AtSym+1) || (Period == Length ) || (Space  != -1)){  
			alert('Please enter a valid email address.');
			}
		else
		{
			return true;
		}
	}
			
function validatecontactdetails(){
	if (document.contactdetails.clientname.value == '')
	{
		alert ('Please enter your Name.');
		return false;
	}
	if (document.contactdetails.clientaddress.value == '')
	{
		alert ('Please enter your address details.');
		return false;
	}	
	if (document.contactdetails.clientemail.value == '')
	{
		alert ('Please enter an Email.');
		return false;
	}
	else
	{
		if (IsEmailValid())
		{
			if (document.contactdetails.clientcountry.value == '')
			{
				alert ('Please select your Country.');
				return false;
			}
			else
			{
				if (document.contactdetails.tandcaccept.checked == true)
					document.contactdetails.submit();
				else
				{
					alert ('Please read and accept the terms and conditions before continuing.');
					return false;
				}
			}
		}
		else
		{
			return false;	
		}
	}	
}