function calcTotals() {
		var price_unit = document.getElementById('price_aud').value;
		var quant 		 = document.getElementById('quantity').value;
		var mailexp		 = document.getElementById('mail_exp').value;
		var pricetotal = num2money((parseFloat(price_unit) + parseFloat(mailexp)) * quant);
  	document.getElementById('price_total').innerHTML = pricetotal;
  	}

	function num2money(n_value) {	
		// validate input
		if (isNaN(Number(n_value)))
		return 'error';	
		// save the sign
		var b_negative = Boolean(n_value < 0);
		n_value = Math.abs(n_value);	
		// round to 1/100 precision, add ending zeroes if needed
		var s_result = String(Math.round(n_value*1e2)%1e2 + '00').substring(0,2);	
		// separate all orders
		var b_first = true;
		var s_subresult;
		while (n_value > 1) {
		s_subresult = (n_value >= 1e3 ? '00' : '') + Math.floor(n_value%1e3);
		s_result = s_subresult.slice(-3) + (b_first ? '.' : ',') + s_result;
		b_first = false;
		n_value = n_value/1e3;
		}
		// add at least one integer digit
		if (b_first)
		s_result = '0.' + s_result;	
		// apply formatting and return
		return b_negative
		? s_result + ')'
		: s_result;
		}

	function inscode(cmd, textel) {
		var range;
		// mozilla 6.0 upwards:
		if (window.getSelection) {
			textarea = document.getElementById(textel);
			start		 = textarea.selectionStart;
			end			 = textarea.selectionEnd;			
			before	 = (textarea.value).substring(0, start);
			sel			 = (textarea.value).substring(start, end);
			after		 = (textarea.value).substring(end, textarea.textLength);
			
			textarea.value = before + '['+cmd+']' + sel + '[/'+cmd+']' + after;
			textarea.focus();
			textarea.selectionStart = end + 5 + (cmd.length * 2);
			textarea.selectionEnd = textarea.selectionStart;
			return;
		// mozilla 4:
		} else if (document.getSelection) {
			range	= document.getSelection().createRange();
		// explorer:
		} else if (document.selection) {
			range	= document.selection.createRange();
		} else return;
		if (range.text) {
			range.text = '['+cmd+']'+range.text+'[/'+cmd+']';
		}
	}