var baseURL = "http://chart.apis.google.com/chart?";

function getChartTitle() {
	var chartTitle = "chtt=";
	chartTitle += document.getElementById("chartTitle").value;
	return chartTitle;
}

function getChartType() {
	var chartType = "&cht=";
	chartType += document.getElementById("chartType").value;
	return chartType;
}

function getChartData() {
	var chartData = "&chd=t:";
	chartData += document.getElementById("chartData").value;
	return chartData;
}

function getChartSize() {
	var chartSize = "&chs=";
	chartSize += document.getElementById("chartSize").value;
	return chartSize;
}

function getChartDataLabels() {
	var chartLabels = "&chl=";
	chartLabels += document.getElementById("chartLabels").value;
	return chartLabels;
}

function createChart() {
	var chart = document.getElementById("chart");
	
	var url = baseURL;
	url += getChartTitle();
	url += getChartType();
	url += getChartData();
	url += getChartSize();
	url += getChartDataLabels();

	chart.src = url;
}

function changeChartType() {
	createChart();
}