Function to return value of a specific url parameter
function getParam ( param ) {
var search, data, pairs;
search = window.location.search.substring(1);
data = {};
pairs = search.split('&');
for (var i in pairs) {
var split = pairs[i].split('=')
data[decodeURIComponent(split[0])] = decodeURIComponent(split[1])
}
return data[param];
}