//	Check form for filetype of attachment field and filesize
//	Only allow .pdf or .zip files
function validateUploadForm()
{
	var attachment = document.forms["contactform"]["attachment"].value;
	var error_message = "Please attach your CV.";
	var submitEl = document.getElementById("submit");
	//	confirm user has selected a file
	if (attachment!=null || attachment!="") 
	{
		// check filename ends with .zip or .pdf
		if( (/\.(pdf|doc|docx)$/i).test(attachment) ) 
		{
			submitEl.disabled = true;
			submitEl.value = "Sending...";
			return true;
		} else {
			error_message = "Invalid filename. Please select a different file.";
		}
	}
	submitEl.disabled = false;
	alert( error_message );
	return false;
}