function convert_postcode(postcode_in) {
	var postcode_out = "";
	for (i = 0; i < postcode_in.length; i++) { if (postcode_in.charAt(i) != " ") { postcode_out += postcode_in.charAt(i); } else { postcode_out += "+"; } }
	return postcode_out;
}

function get_directions() {	
	chosen_postcode = "BS1 4QA";
	var converted_chosen_postcode = convert_postcode(chosen_postcode);
	if (document.postcode.postcode_field.value == "Enter postcode for directions") {
		var converted_entered_postcode = convert_postcode(chosen_postcode);
	} else {
		var converted_entered_postcode = convert_postcode(document.postcode.postcode_field.value);
	}
	if (converted_entered_postcode == "" || converted_chosen_postcode == converted_entered_postcode) {
		var oWin = window.open("http://maps.google.co.uk/maps?q="+converted_chosen_postcode, "_blank");
		if (oWin) { if (oWin.focus) oWin.focus(); return false; }
		oWin = null;	
	} else {	
		var oWin = window.open("http://maps.google.com/maps?saddr="+ converted_entered_postcode + "&daddr="+ converted_chosen_postcode +"&hl=en", "_blank");
		if (oWin) { if (oWin.focus) oWin.focus(); return false; }
		oWin = null;
	}		
}