function validateInterpretation()
{
	var f = document.interpretfrm;

	if(trimString(f.cust_name.value) == '')
		return showError(f.cust_name, 'Please provide name');

	if(trimString(f.cust_email.value) == '')
		return showError(f.cust_email, 'Please provide email address');

	if ((f.cust_email.value.indexOf ('@',0) == -1) || (f.cust_email.value.indexOf('.', 1) == -1) || f.cust_email.value.indexOf(' ', 1) != -1)
			return showError(f.cust_email, 'Invalid email address');

	if(trimString(f.cust_phone.value) == '')
		return showError(f.cust_phone, 'Please provide your telephone number');

	if(trimString(f.cust_lang.value) == '')
		return showError(f.cust_lang, 'Please provide your language');

	if(trimString(f.clients_lang.value) == '')
		return showError(f.clients_lang, 'Please provide client language');

	if(trimString(f.time_zone.value) == '')
		return showError(f.time_zone, 'Please provide a time zone');

	if(trimString(f.duration.value) == '')
		return showError(f.duration, 'Please provide duration of conference');

	if(!chkDecimalNumeric(f.duration.value))
		return showError(f.duration, 'Duration should be numeric value');

	f.submit_button.disabled = true;
	return true;
}